• 301 Redirects
  • File Compression
  • Code Minification
  • DDoS
  • Botnet
  • IP address
  • OSI Model
  • HTTP
  • SYN Flood attack
  • TCP ( Transmission Control Protocol)
  • IP Spoofing
  • DNS Amplification
  • WAF ( Web Application Firewall )
  • Anycast
  • Internet of Things
  • Brute force attack
  • Man in the middle attack
  • Credential Stuffing
  • Data breach
  • SSL/ TLS Encryption
  • RTT ( Round Trip Time )
  • Internet exchange point
  • Ransomware
  • FirewallD
  • IP Tables
  • CSRF (Cross-site request forgery)
  • XSS (cross-site scripting)
  • Confused Deputy
  • Client-side code
  • WPO ( Web Performance Optimisation )
  • APM ( Application Performance Monitoring )
  • RUM ( Real User Monitoring )
  • Real Browser Monitoring
  • FEO ( Front end optimisation )
  • Waterfall chart
  • Time to Title
  • Time to start render
  • Time to Display
  • Time to interact
  • Caching
  • RWD ( Responsive design )
  • Adaptive Web Design (AWD)
  • Omnichannel
  • IaaS
  • Web Application
  • Static Content
  • Dynamic content
  • Third party tags
  • Benchmarking Performance
  • SLA (Service Level Agreement)
  • Shopping Cart Optimisation
  • User Context
  • User Experience (UX)
  • User Interface (UI)
  • Conversion Rate Optimization (CRO)
  • Bounce Rate
  • Scalability
  • Sequencing
  • Critical Rendering Path
  • DD4BC
  • Hyper Text Transport Protocol Secure (HTTPS)
  • Domain Sharding
  • CSS Sprite
  • Concatenation
  • Lossless Compression
  • GZIP
  • Last Mile
  • Middle Mile
  • Image Compression
  • Landing Page
  • Load Time
  • Page weight
  • Browser Caching
  • Proxy Server
  • Reverse Proxy
  • Edge Computing
  • Time to live
  • DNS (Domain Name Systems)
  • DNS recursor
  • Root Server
  • TLD nameserver
  • Authoritative nameserver
  • WebP
  • Structural Similarity Index (SSIM)
  • Hop
  • Network segment
  • Peering
  • Uniform Resource Identifier (URI)
  • Load balancing (computing)
  • Computer cluster
  • VP8
  • Libvpx
  • GIF (Graphics Interchange Format)
  • WebRTC
  • AOmedia
  • WebM
  • BSD licenses
  • ICC profile
  • Extensible Metadata Platform
  • Open standard
  • Portable Network Graphics
  • pngcrush
  • Video coding format
  • Image File Formats
  • Raster graphics
  • Pixel
  • Color depth
  • Optical character recognition(OCR)
  • Color space
  • Color model
  • Page description language (PDL)
  • Graphics Device Interface (GDI)
  • Palette
  • Routing information base (RIB)
  • Static routing
  • Reverse-path forwarding (RPF)
  • Routing loop
  • Packet shaping
  • Bandwidth throttling
  • Area border router (ABR)
  • Traffic policing
  • Traffic contract
  • High availability
  • Cache engine
  • Fault tolerance
  • Dropped Packets
  • Jitter
  • Resource Reservation Protocol (RSVP)
  • Multiprotocol label switching (MPLS)
  • Differentiated Services (DiffServ, or DS)
  • Integrated services or IntServ
  • PCI Express(PCI-E)
  • Kernel
  • Thread block
  • CUDA (Compute Unified Device Architecture)
  • Configuration files
  • Distributed computing
  • Loader
  • Power-on self-test (POST)
  • Boot loader
  • Legacy system
  • memory bus
  • system bus
  • address bus
  • Pixel pipelines
  • Bypass airflow
  • Equipment footprint
  • In-row cooling
  • raised floor
  • server cage
  • Internet radio appliance
  • control bus
  • peripheral device
  • Memory
  • memory address
  • dual inline memory module (DIMM)
  • Central processing unit cache (CPU cache)
  • Core memory
  • program counter (PC)
  • Read-only memory (ROM)
  • Non-volatile memory (NVM)
  • Basic input/output system (BIOS)
  • Programmable Read-Only Memory (PROM)
  • Electrically Erasable Programmable Read-Only Memory (EEPROM)
  • expanded memory specification (EMS)
  • Firmware
  • Read-write memory (RWM)
  • Write-only memory (WOM)
  • Device driver
  • Boot sector
  • Extended system configuration data (ESCD)
  • Beep code
  • Boot sequence
  • Master boot record (MBR)
  • Volume boot record (VBR)
  • Boot sector virus
  • Banker Trojan
  • Binder
  • Blended threat
  • Blind drop
  • Non-Volatile Random Access Memory (NVRAM)
  • MIDlet
  • Mobile Internet Device (MID)
  • Joint application development (JAD)
  • Enterprise resource planning (ERP)
  • Rapid application development (RAD)
  • Ensemble programming
  • Network Based Application Recognition (NBAR)
  • Architected rapid application development (ARAD)
  • Rapid mobile application development (RMAD)
  • Access modifiers
  • Mobile computing device
  • Ultra Mobile PC (UMPC)
  • Perfect RAM
  • Personal Identifiable Information (PII or pii)
  • Browser modifier
  • Trojan horse
  • Malicious software
  • Clickjack attack
  • Unified threat management (UTM)
  • Integrated threat management (ITM)
  • Zero-day threat
  • Bugbear
  • Access control list (ACL)
  • Delegate
  • interrupt request (IRQ)
  • Industry Standard Architecture (ISA)
  • Plug and Play (PnP)
  • Device manager
  • Certified Output Protection Protocol (COPP)
  • File Compression
  • Lossy Compression
  • Vector Graphics
  • Cloud Based
  • SSL (Secure Sockets Layer)
  • Hotlink Protection
  • 404 Errors
  • Yslow Score
  • 3rd Party Request
  • Webpage Testing
  • PageSpeed
  • Pagelocity
  • GT Matrix
  • FMP (First Meaningful Paint)
  • CSS (Cascading Style Sheets)
  • VPS (Virtual Private Server)
  • IOPS
  • Latency
  • Elapsed Time
  • Performance Thresholds
  • Multivariate Testing
  • Throughput
  • TTFB
  • SRC Set
  • Image Sprite
  • SVG
  • Payload Computing
  • Log File
  • Web Font Performance
  • Webpage Test
  • Page Speed
  • PWA (Progressive Web App)
  • Accessibility
  • First CPU Idle
  • First Input Delay (FID)
  • Saturation
  • Datacenter
  • Feature Flags
  • Feature Rollout
  • Lead Generation
  • Hero Image
  • Heat Map
  • Headline Testing
  • Growth Hacking
  • Multi Armed Bandit
  • Split Testing
  • Squeeze Page
  • Type 1 Error
  • Type 2 Error
  • Viewable Impression
  • CTR (Click Through Rate)
  • Client Site Tasting
  • Data Layer
  • Macro Conversion
  • Micro Conversion
  • Affiliate
  • Alt Text
  • Anchor Text
  • Backlink
  • cPanel
  • PostgreSQL
  • NetScaler
  • Metadata
  • Cache Control
  • HTTP Compression
  • Resource Hints
  • Load Impact
  • PHP accelerators
  • Cyber Flood
  • Wpdb(WordPress Database)
  • JavaScript
  • FiOS
  • ImageAlpha
  • Media Attribute
  • Pixel Density
  • Visibility
  • Usability
  • Pingdom
  • CloudFlare
  • Lighttpd
  • HyperDB
  • Content Optimization
  • Performance Counter
  • Argo Smart Router
  • Server Push
  • Varnish Cache
  • TLS (Transportation Layer Security)
  • FCP (First Contentful Paint)
  • DCL (Dom Content Loaded)
  • Field Data
  • Time to Interactive (TTI)
  • Bandwidth
  • Redis
  • Anxiety Elements
  • Cookie
  • Eyetracking
  • From
  • Friction
  • Incentives
  • Landing Page Optimization
  • Latent Conversion
  • Longtail Keyword
  • Microsite
  • Personalization
  • Value Exchange
  • Server Load
  • Headers
  • W3TC
  • Concurrent Users
  • Request Per Second
  • Error Rate
  • Peak Response Time
  • Parallelism
  • Backbone
  • Critical Path
  • E2E (End 2 End ) Page Load Performance
  • Forward Proxy
  • JavaScript Blocking
  • Code Profiling
  • Complex Test Layout
  • SOAP Monitoring
  • DOM (Document Object Model)
  • Consistently Interactive
  • Semrush
  • Kernel32.dll
  • Unified Extensible Firmware Interface (UEFI)
  • Bricking
  • Host-based modem
  • Virtual memory
  • Connected Limited Device Configuration (CLDC)
  • JXTA
  • Peer-to-peer architecture (P2P architecture)
  • IETF (Internet Engineering Task Force)
  • SDP (Session Description Protocol)
  • UDP (User Datagram Protocol)
  • OLTP (online transaction processing)
  • Web Standards Project (WaSP)
  • Connect Time
  • Information scent
  • Life Time Value (LTV)
  • Visitor segmentation
  • Server-side testing
  • User journey map
  • User flow
  • Usability testing
  • Web analytics
  • Exploratory stress testing
  • Continuous Delivery
  • OCSP stapling
  • Greynet
  • Thin client
  • Data definition language (DDL)
  • Microsoft Interface Definition Language (MIDL)
  • Sharding
  • DNS prefetching
  • Prerendering
  • Key performance indicators (KPI)
  • Remote monitoring and management (RMM)
  • Routing and remote access service (RRAS)
  • Remote Authentication Dial-In User Service (RADIUS)
  • Professional services automation (PSA)
  • Authentication, authorization and accounting (AAA)
  • Server-side scripting
  • Progressive Enhancement (PE)
  • Graceful degradation
  • Unobtrusive JavaScript
  • Software brittleness
  • Failure transparency
  • Fail-fast
  • Control reconfiguration
  • Failure semantics
  • Resilience
  • Multipath routing
  • Data redundancy
  • Data scrubbing
  • Crash-only software
  • Comma separated values (CSV)
  • Z Object Publishing Environment (Zope)
  • Abstract IL
  • Granularity
  • Vectorization
  • Parallelization
  • Coprocessor
  • Hardware Threads
  • Memory traffic
  • Memory Bandwidth
  • Cache Hit Rates
  • L1 Cache
  • Memory Hierarchy
  • Network Optimization
  • Iteration Loop
  • Static web page
  • Static URL
  • Aspect-oriented programming (AOP)
  • Modularity
  • Modular programming
  • Single-sourcing
  • Module
  • Source code
  • Masthead
  • Dynamic URL
  • Enterprise Feedback Management (EFM)
  • Scripting engine
  • Visual Basic Script (VBScript)
  • Logic error
  • Shared Source
  • Extensible Markup Language (XML)
  • Command line interface (CLI)
  • Command prompt
  • Syntax error
  • Programming logic
  • Runtime error
  • Design pattern
  • Command-line option
  • Object-oriented programming (OOP)
  • Markup language
  • Run time
  • DETFF (Dual Edge-Triggered FlipFlop)
  • SETFF (Single Edge Triggered Flip Flop)
  • Timing Parameters
  • Timeouts
  • Dashboard
  • Subroutines
  • Channel Flow
  • Balanced scorecard
  • Resident Threads
  • Running Threads
  • L2 Cache
  • Memory Access Pattern
  • Texture Memory
  • Effective Bandwidth
  • GMA (Global Memory Access)
  • Greatest Impact
  • Vector Registers
  • Row/ Column Major Order
  • Peak Bandwidth
  • Memory Allocations
  • Dalvik
  • Compile
  • Link time
  • Drill Down
  • Self Tuning
  • Quicksort
  • Adaptive Control
  • PAPI (Performance Application Programming Interface)
  • Code Quality
  • Flexbox
  • Flex Container
  • Flex Item
  • Flex Wraps
  • Blockers
  • Agile Content Development
  • Broken Links
  • Defective Links
  • Crawlers
  • Keyword Proximity
  • Meta Title
  • Flex Bugs
  • Relevance
  • Keyword Stuffing
  • Keyword Density
  • Link Juice
  • Google Search Console
  • Content Score
  • Domain Trust
  • Cloaking
  • Rich Snippets
  • Meta Description
  • No Follow Attributes
  • Paid Listing
  • Progressive Web Apps
  • Sitemap.xml
  • Use Intent
  • Robots.txt
  • Server Speed
  • Graphics
  • Keyword Canonization
  • File Sizes
  • Focus
  • Authority Site
  • App Personalization
  • Bayesian
  • Baseline
  • Campaign Scheduling
  • Churn Rate
  • Clickbait
  • Canonical URL
  • Clickstream
  • Breadcrumb Navigation
  • Cross Domain Tracking
  • Click Area
  • Directional Clues
  • Date Range Filter
  • Drop-Off
  • Do Not Track
  • Exit pop-up
  • Experience Optimization
  • Eye Flow
  • Field Level Statistics
  • Feature Testing
  • Funnel Testing
  • Feature Rollout
  • Gamification
  • Geo Fencing
  • Geo Targeting
  • Hesitation Time
  • Hypothesis
  • JS Variable
  • UUID Unique Visitors
  • Leads
  • Null Hypothesis
  • Qualitative Visitors Research
  • Below the fold
  • Breadcrumbs
  • Content Management System (CMS)
  • CSS framework
  • Deprecated
  • Elastic layout
  • EM
  • Embedded style
  • FOLD
  • HIT
  • RPV (Revenue Per Visitor )
  • Scarcity
  • Server Site Testing
  • Split Url Testing
  • Standard Error
  • Scroll Map
  • Title Tag
  • Test Hypothesis
  • Trust Badges
  • Test Duration
  • User Testing
  • User Generated Content
  • Whitespace
  • Widgets
  • Z Index
  • Hreflang Attribute
  • Infographics
  • Interstitials
  • Keyword Cannibalization
  • Keyword Stemming
  • Link Farm
  • Link Hoarding
  • Usability
  • Search Term
  • Search Term Registration
  • Search Engine Spam
  • Meta Search Term
  • LAMP
  • SGML
  • SOAP
  • TAG
  • Synthetic monitoring
  • First meaningful paint
  • Input latency
  • Render start
  • First paint
  • Total page weight
  • Number of requests
  • DOM Nodes
  • Visitor
  • Returning visitor
  • Site audit
  • Uptime
  • Crawler error
  • Dead end page
  • Duplicate content
  • Benchmark
  • Reachability
  • Stickiness
  • Competitive intelligence
  • Entry page
  • Exit page
  • Minutes per visit (time on site)
  • Session
  • Social referrals
  • Performance testing
  • Load testing
  • Stress testing
  • Application stress testing
  • Transactional stress testing:
  • Systemic stress testing
  • Volume testing
  • Performance tuning
  • Session management
  • Session ID
  • Simultaneous users
  • Endurance (Soak) testing
  • Spike testing
  • Baseline testing
  • Benchmark testing
  • Capacity
  • Capacity testing
  • Investigation
  • Component testing
  • Smoke testing
  • Return Of Investments (ROI)
  • Unit test
  • Behavioral Targeting
  • CPL (Cost Per Lead)
  • Custom Variables
  • Enhanced Ecommerce Report
  • Event Tracking
  • Flow Visualization
  • Goal Funnels
  • Social Logins
  • Quality Assurance
  • Mobile Site
  • Validation test
  • Ramp up period
  • Ramp down period (Shutdown time)
  • Workload
  • Distributed (Remote) testing
  • Agent (Slave)
  • Master
  • Stop test
  • Shutdown test
  • MIME type
  • Think time (user delay)
  • Samplers
  • Logic controllers
  • Listeners
  • Configuration elements
  • Assertions
  • Timers
  • Pre-processors
  • Post-processors
  • Proxy
  • JMeter variables
  • JMeter properties
  • System properties
  • User properties
  • Metrics
  • Network-specific metrics
  • Platform-specific metrics
  • Application-specific metrics
  • Service-level metrics
  • Business metrics
  • Performance acceptance criteria
  • Implement test design
  • Execute the tests
  • Scenarios
  • Testing environment
  • Configure test environment
  • Staging environment
  • Production environment
  • Dynamic data
  • Memory leaks
  • Minimum time
  • Maximum time
  • Average
  • Percentile
  • Normal value
  • Outliers
  • User Abandonment
  • Performance requirements
  • Performance goals
  • Performance targets
  • Performance objectives
  • Performance testing objectives
  • Performance Budgets
  • Resource utilization
  • Setup
  • Teardown
  • Motivation
  • Mobile Optimization
  • Conversion Path
  • Anxiety Elements
  • Double Opt-in
  • Post Back
  • Tracking Pixel
  • Single Opt-in
  • Case Attribute
  • Conformance Checking
  • Cycle Time
  • Data Extraction
  • ETL
  • Event Log
  • Idle Time
  • Key Figure
  • Lean Management
  • Optimization Potential
  • Process Loop
  • Process Execution
  • Process Path
  • Reference Process
  • Root Cause Analysis
  • Waiting Time
  • Work 4.0
  • Test Objective
  • Tailing Value / Visit
  • Cookie Churn
  • Casual Interference
  • Error Spending Function
  • Error Probability
  • Effect Size
  • Factorial Design
  • Futility Boundary
  • Frequentist Inference
  • CDN

    A content delivery network or content distribution network is a geographically distributed network of proxy servers and their data centers. The goal is to provide high availability and high performance by distributing the service spatially relative to end-users --Read More

    301 Redirects

    A 301 redirect indicates the permanent moving of a webpage from one location to another. Its refers to HTTP status code of the page.

    File Compression

    File compression is a data compression method in which the logical size of a files is reduced to save disk space for easier and faster transmission over a network or the internet. It also Known as File Zipping.

    Code Minification

    It is the process of compression code from the original size to the smallest size and does not affect the operation of the code.


    A DDoS (Distributed Denial of Service) attack is an attempt to exhaust a network, application or service\'s available resources so that genuine users can not obtain entry.


    A botnet relates to a set of malware-infected computers that have been controlled by a malicious actor.

    IP address

    The Internet Protocol (IP) is the Internet address system and has the key role of providing information packets to a target computer from a source device.IP is the most important way of connecting the network and it provides the foundation of the Internet.

    OSI Model

    The OSI model is a conceptual model developed by the International Organisation for standardization, which permits various communications technologies to interact through standard protocols. In plain English, the OSI offers a standard for the communication of various software devices.


    HTTP is an application layer protocol intended to transmit data between networked machines and operates in addition to other network protocol stack layers.The Hypertext Transfer Protocol (HTTP) is the foundation of the World Wide Web, and is used to load web pages using hypertext links.

    SYN Flood attack

    A SYN flood is a sort of denial-of-service (DDoS) attack aimed at making a server inaccessible to legitimate users by consuming all accessible server resources. The attacker can overwhelm all available ports on a targeted server machine by repeatedly sending initial request for connection (SYN) packets, causing the targeted device to respond slowly or not at all to legitimate traffic.

    TCP ( Transmission Control Protocol)

    TCP is used in combination with IP to keep a link between the sender and the target and to ensure the order of the packet.

    IP Spoofing

    IP spoofing is the creation of Internet Protocol (IP) packets with a modified source address to either hide the sender\'s identity, to impersonate a different computer system, or both.

    DNS Amplification

    It is a reflective volumetric continuous denial-of-service (DDoS) assault in which an attacker leverages the accessible DNS resolver features to overwhelm a target server or network with increased requests, making the server and its surrounding infrastructure inaccessible.

    WAF ( Web Application Firewall )

    A WAF or Web Application Firewall enables to safeguard web applications by controlling and tracking HTTP flows between the Internet and a web application.


    Anycast is a network addressing and routing technique that allows incoming requests to be transmitted to various places or \"servers.\"

    Internet of Things

    The Internet of Things is a catchall expression for all the different systems connected to the internet which are not traditional computers.This involves everything from intelligent clocks and fitness trackers to intelligent refrigerators, headphones, phones, washing machines, vehicles, traffic lights, aircraft engines, and home security systems.

    Brute force attack

    A brute force attack is a technique of decoding sensitive information using trial-and-error. What distinguishes brute force attacks from other cracking techniques is that brute force attacks do not use an intellectual strategy ; they merely attempt to use distinct character types until the right combination is discovered.

    Man in the middle attack

    Attackers place themselves between two devices (often a web browser and a web server) in a man-in - the-middle attack and monitor or alter connections between the two. Then the attackers can gather data and impersonate either of the two officials.

    Credential Stuffing

    Credential stuffing is a cyber attack in which credentials acquired on one system from a data breach are used to try to sign in to another unrelated system.

    Data breach

    A data breach is the transfer of confidential, personal, or otherwise vulnerable information into an unsecured environment An infringement of data may happen accidentally or as a consequence of an intentional attack.

    SSL/ TLS Encryption

    Transport Layer Security (TLS) is a protocol for encrypting data that is sent over the Internet. TLS grew out of Secure Sockets Layer (SSL), the first widely-adopted web encryption protocol, in order to fix most of the earlier protocol’s security flaws. The industry still uses the terms somewhat interchangeably for historical reasons.

    RTT ( Round Trip Time )

    Round-trip time (RTT) is the time it takes for a network request to go from a starting point to a destination and back to the starting point in milliseconds (ms). RTT is an important measure for determining the safety of a local network or Internet link and is widely used by network administrators to diagnose network link speed and efficiency.

    Internet exchange point

    An Internet Exchange Point (IXP) is a physical place through which Internet infrastructure businesses such as ISPs and CDNs communicate to each other.


    Ransomware is malware that encrypts files on your desktop/laptop or locks you out entirely.It\'s distributed by hackers who then request a ransom claiming you\'ll get the decryption button to restore your data if you pay the desired amount.


    firewalld is a firewall management tool for Linux operating systems. It provides firewall features by acting as a front-end for the Linux kernel\'s netfilter framework via the nftables user space utility (before v0.6.0 iptables backend), acting as an alternative to the nft command line program.

    IP Tables

    iptables is a user-space utility program that allows a system administrator to configure the tables provided by the Linux kernel firewall(implemented as different Netfilter modules) and the chains and rules it stores. Different kernel modules and programs are currently used for different protocols; iptables applies to IPv4, ip6tables to IPv6, arptables to ARP, and ebtables to Ethernet frames.

    CSRF (Cross-site request forgery)

    A cross-site request forgery assault is a sort of confused deputy cyber attack that forces a customer into using their records accidentally to invoke a state-changing exercise, such as moving money from their register, altering their email address and password, or some other undesirable behavior.

    XSS (cross-site scripting)

    Cross-site scripting (XSS) is an exploit in which the attacker attaches code to a legitimate website which will be executed when the victim loads the website. It is possible to insert malicious code in several ways. Most popularly, it is either introduced to the end of a URL or published straight to a website displaying user generated content.

    Confused Deputy

    A confused deputy relates to a computer program which is fooled into misusing its authority.

    Client-side code

    Client-side code is JavaScript code that runs on a user’s machine which is executed by the web browser after the browser loads a web page. Client-side code is very useful with interactive webpages; interactive content runs faster and more reliable since the user’s computer doesn’t have to communicate with the web server every time there is an interaction.

    WPO ( Web Performance Optimisation )

    WPO is the process, methodology and various techniques for measuring, benchmarking and improving the performance of the application, where performance refers to the speed at which application pages are rendered on the browser of the end-user.

    APM ( Application Performance Monitoring )

    Application performance monitoring relates to a wide range of tracking methods to determine web applications\' quality, accessibility, and consistency.

    RUM ( Real User Monitoring )

    This sort of APM alternative, requires performance data from real customer visits as they occur through a JavaScript inserted into the browser.

    Real Browser Monitoring

    This sort of APM utilizes a real computer-operated browser to automatically evaluate the efficiency of a web application.

    FEO ( Front end optimisation )

    Front-end performance refers to how fast the browser of a visitor can execute and render the content of the application once it is downloaded.

    Waterfall chart

    A waterfall chart is a graphical depiction of the load cycle of a page. It displays every asset that makes up a web or mobile application visually and uses horizontal bars to show how long each asset has taken to download.

    Time to Title

    The period elapsed from the moment a file is requested by the user until the file name arrives in the browser tab.

    Time to start render

    The time elapsed from the moment the user asks for a file to the moment the page\'s graphic elements begin appearing in the browser.

    Time to Display

    The period elapsed from the moment the customer requests a page until all of the page\'s graphic components are created.

    Time to interact

    The time elapsed from the moment the customer requests a page until the visitor can fully use the app page, scroll, interact with components, and click links


    Caching is the method by which information is stored in a cache. A cache is a high-speed data storage layer that holds a typically temporary sub-set of information so that future requests for that information are serviced quicker than possible by accessing the primary storage place of the data.

    RWD ( Responsive design )

    Responsive web design is a web design method that aims at achieving a quality user experience with the same URL on a computer of any size.

    Adaptive Web Design (AWD)

    Another strategy to designing multiple equipment is adaptive web design. It focuses on the concept of adjusting a web application on the server side to suit the device of the customer, rather than on the browser of the customer (user), as is the situation with RWD.


    Omni-channel relates to a synchronized strategy that retailers use to interact with and serve clients across various touchpoints, including internet, mobile, in-store, and more.


    Infrastructure-as-a-Service is a cloud computing near-synonym. It defines the supply and use of hardware that a separate provider owns and operates.

    Web Application

    Web apps are application programs that are stored on a remote server and delivered over the Internet via a browser interface, often referred to as the client.

    Static Content

    All content that is not automatically updated is called static content. The fundamental design, navigation components, pictures, and text are all stationary on most web applications and can therefore be placed in a cache, either on a CDN or in the user\'s browser locally.

    Dynamic content

    Dynamic content is something that is either customized to the user or modified in real time on a web page. For performance, it is an important distinction, as dynamic content must always be retrieved from its origin rather than cached. This means that optimization is difficult.

    Third party tags

    Tags are bits of code, often JavaScript, attached to a web page to offer features such as tracking, analytics, A / B testing, social media inclusion, and much more. Since they are mostly provided by a service provider (rather than in-house built and operated), they are referred to as third party tags.

    Benchmarking Performance

    To set objectives for a WPO initiative, many businesses benchmark their web performance against other web applications, particularly rivals. The concept is that there is no universal \"magic\" figure or measure, defining quality performance — only by analysing the present situation can it be evaluated.

    SLA (Service Level Agreement)

    In the internet sector, SLAs are frequently used when contracting with a service provider, such as cloud storage, hosting, or CDN facilities. The SLA defines precise thresholds for the successful delivery of the service that must at least be met in order to be valid for the contract terms.

    Shopping Cart Optimisation

    Optimizing a simple checkout method enables retailers account for clients throughout the purchase phase using multiple devices. Offering an omni-channel experience is much easier when the checkout process is simple.

    User Context

    Context is frequently mentioned when discussing web performance and user experience, as the circumstances of user’s visit are very important for page speed. For example, a user on a mobile device with a slow 3 G connection will have a different experience compared to a user on a desktop. Specific customer contexts must be drawn into consideration when operating on performance optimization and certain steps should be taken to resolve quality issues for particular situations.

    User Experience (UX)

    User experience is the word that encompasses how the customer interacts with a web application. It implies contemplating everything from initial page load performance to websites layout and features to transaction processing.

    User Interface (UI)

    UI is merely shorthand for the front-end in the framework of internet applications — the portion that the customer observes and interacts with. It is most commonly used when discussing websites and SaaS apps that involve a lot of user interaction, such as online banking, telephone, or business tools.

    Conversion Rate Optimization (CRO)

    CRO is an approach to developing and optimizing internet websites to cause certain customer behaviors, most particularly converting on a task like buying or downloading content.

    Bounce Rate

    Bounce rate is the percentage of all web app visitors who leave after only one page view. High bounce rates are a sign that the performance of your website is slow or that your content does not meet the expectations of the user.


    Scalability relates to a system\'s capacity to manage growth or development and its accompanying requirements. Scalable devices can be adapted rapidly to satisfy a rapidly expanding company\'s requirements, or a blog that unexpectedly encounters a demand rise.


    Sequencing, or sequencing of applications, is a method of prioritizing and controlling content rendering on a web page. It is feasible to manipulate the flow of items through a reverse proxy that scans and recognizes the document object model (DOM), thus overriding the normal trends of the browser.

    Critical Rendering Path

    The critical rendering path is a term used to describe a browser\'s natural sequence to start rendering a web page. It involves downloading and studying the HTML, downloading and parsing any CSS and JavaScript files that are requested in the HTML, and verifying that it is protected on all bases (so that nothing breaks when rendering begins).


    DD4BC is a cyber-extortion organization best recognized for using DDoS and requests from Bitcoin. The group starts by sending ransom emails that threaten DDoS attacks of 400 Gbps unless a certain amount of Bitcoin is paid.

    Hyper Text Transport Protocol Secure (HTTPS)

    HTTP is the best-known web address prefix, but it is often substituted by HTTPS, which includes session management by a security protocol. Transport Layer Security (TLS) or Secure Socket Layer (SSL) can be used as a sublayer for locations with HTTPS.

    Domain Sharding

    When a site is \"sharded,\" its resources are deliberately split across multiple domains to allow accelerated loading. This is mainly an obsolete method and will be further obsolete with the adoption of HTTP 2.0.

    CSS Sprite

    A number of images are combined in a CSS sprite, typically small images, to form a single graph. Using CSS directions, the different parts of this larger graphic are placed around the website. This strategy reduces bandwidth and optimizes website loading as it reduces the total amount of pictures to be retrieved.


    In an attempt to save space, concatenation includes connecting two or more character strings. Then the concatenated character strings are addressed as one element, reducing time for retrieval (less demands implies less browser job and quicker rendering).

    Lossless Compression

    Data is encoded for a lighter weight in lossless compression without compromising the original resolution. Despite maintaining complete performance, the decrease in file size is small compared to that given by loss compression.


    Gzip is a popular file format for compression and decompression, reducing file size and eventually minimizing bandwidth costs. The process is completed in the background, leaving the end user unaware of the compression of the data.

    Last Mile

    The last mile is the route, data must travel in order to reach the device of the user from the edge of the internet. This could be the broadband connection of an Internet service provider to a house or company, or the wireless transmission of a cellular network from a building to a smartphone.

    Middle Mile

    The middle mile is the path data travels from the server of a business to the edge of the internet where it meets a provider of internet service. It consists of a number of server \"hops\" that make up the internet\'s backbone, as well as CDN nodes. It is possible to optimize routes within the middle mile to reduce latency.

    Image Compression

    Image compression is the method of implementing data compression to reduce file size of images and is one of the most significant measures in completing image optimization.

    Landing Page

    Landing pages are website pages that visitors see first. The homepage is often a landing page, but when a customer comes from a google results page they may land on an inside section such as a category page or a particular product page.

    Load Time

    It shows how long it takes for a page to fully load into the browser after a user clicks a link or submits an application. There are many factors affecting the load time of the page.

    Page weight

    Page weight is the total data of all the file resources needed to load a page, such as HTML, CSS, JavaScript and images, as well as loaded files from third party sources such as font services and external plugins.

    Browser Caching

    Browser caching is a technique that temporarily stores, part or most of the recently used Web pages and data in a Web browser. It is used by local downloading web page parts in the browser cache to boost the browsing velocity of a user.

    Proxy Server

    A proxy server will verify and forward incoming client applications for further communication to other servers. A proxy server, is situated between a client and a server where it functions as an intermediary between the two, like a Web browser and a Web server.

    Reverse Proxy

    A reverse proxy is a server located in front of one or more web servers that intercepts client requests. This is distinct from a forward proxy in which the proxy is placed in front of the customers. When clients send requests to a website\'s origin server with a reverse proxy, those requests are intercepted by the reverse proxy server on the edge of the network. The reverse proxy system will then submit applications to the origin server and obtain answers.

    Edge Computing

    Edge computing is a networking philosophy that aims to bring computing as close as possible to the database to decrease latency and bandwidth use. Simply put, edge computing implies operating fewer cloud processes and transferring those processes to local locations, such as a user\'s desktop, an IoT device, or an edge server.

    Time to live

    Time to live (TTL) refers to the amount of time or “hops” that a packet is set to exist inside a network before being discarded by a router. TTL is also used in other contexts including CDN caching and DNS caching.

    DNS (Domain Name Systems)

    The Domain Name Systems (DNS) is the phonebook of the Internet. Humans access information online through domain names, like nytimes.com or espn.com. Web browsers interact through Internet Protocol (IP) addresses. DNS translates domain names to IP addresses so browsers can load Internet resources.

    DNS recursor

    The DNS recursor is a server designed to receive queries from client machines through applications such as web browsers. Typically the recursor is then responsible for making additional requests in order to satisfy the client’s DNS query.

    Root Server

    The root server is the first step in translating (resolving) human readable host names into IP addresses. Typically it serves as a reference to other more specific locations.

    TLD nameserver

    This nameserver is the next step in the search for a specific IP address, and it hosts the last portion of a hostname (In example.com, the TLD server is “com”).

    Authoritative nameserver

    The authoritative nameserver is the last stop in the nameserver query. If the authoritative name server has access to the requested record, it will return the IP address for the requested hostname back to the DNS Recursor (the librarian) that made the initial request.


    WebP is a modern image format that provides superior lossless and lossy compression for images on the web. Using WebP, webmasters and web developers can create smaller, richer images that make the web faster.

    Structural Similarity Index (SSIM)

    The Structural Similarity Index (SSIM) is a perceptual metric that quantifies image quality degradation* caused by processing such as data compression or by losses in data transmission. It is a full reference metric that requires two images from the same image capture— a reference image and a processed image.


    In computer networking, including the Internet, a hop occurs when a packet is passed from one network segment to the next. Data packets pass through routers as they travel between source and destination. The hop count refers to the number of intermediate devices through which data must pass between source and destination.

    Network segment

    A network segment is a portion of a computer network. The nature and extent of a segment depends on the nature of the network and the device or devices used to interconnect end stations.


    In computer networking, peering is a voluntary interconnection of administratively separate Internet networks for the purpose of exchanging traffic between the users of each network. The pure definition of peering is settlement-free, also known as \"bill-and-keep,\" or \"sender keeps all,\" meaning that neither party pays the other in association with the exchange of traffic; instead, each derives and retains revenue from its own customers.

    Uniform Resource Identifier (URI)

    A Uniform Resource Identifier (URI) is a string of characters that unambiguously identifies a particular resource. To guarantee uniformity, all URIs follow a predefined set of syntax rules but also maintain extensibility through a separately defined hierarchical naming scheme (e.g. http://).

    Load balancing (computing)

    In computing, load balancing improves the distribution of workloads across multiple computing resources, such as computers, a computer cluster, network links, central processing units, or disk drives. Load balancing aims to optimize resource use, maximize throughput, minimize response time, and avoid overload of any single resource.

    Computer cluster

    A computer cluster is a set of loosely or tightly connected computers that work together so that, in many respects, they can be viewed as a single system. Unlike grid computers, computer clusters have each node set to perform the same task, controlled and scheduled by software.


    VP8 is an open and royalty free video compression format owned by Google and created by On2 Technologies as a successor to VP7.


    libvpx is a free software video codec library from Google and the Alliance for Open Media (AOMedia). It serves as the reference software implementation for the VP8 and VP9 video coding formats, and for AV1 a special fork named libaom that was stripped of backwards compatibility. As free software it is published also in source code under the terms of the revised BSD license. It ships with the command line tools (vpxenc/aomenc and vpxdec/aomdec) that build on its functionality.

    GIF (Graphics Interchange Format)

    The Graphics Interchange Format is a bitmap image format that was developed by a team at the online service provider CompuServe led by American computer scientist Steve Wilhite on June 15, 1987. It has since come into widespread usage on the World Wide Web due to its wide support and portability between many applications and operating systems.


    WebRTC (Web Real-Time Communication) is a free, open-source project that provides web browsers and mobile applications with real-time communication (RTC) via simple application programming interfaces (APIs). It allows audio and video communication to work inside web pages by allowing direct peer-to-peer communication, eliminating the need to install plugins or download native apps. Supported by Apple, Google, Microsoft, Mozilla, and Opera, WebRTC is being standardized through the World Wide Web Consortium (W3C) and the Internet Engineering Task Force (IETF).


    The Alliance for Open Media (AOMedia) is a non-profit industry consortium for the development of open, royalty-free technology for multimedia delivery headquartered in Wakefield, Massachusetts, USA. It adopts the principles of the development of open web standards for the creation of video standards that can serve as royalty-free alternatives to the hitherto dominant standards of the Moving Picture Experts Group (MPEG) and the related business model that exploits intellectual property through patent royalties and became associated with financial uncertainties, especially for internet companies and innovators.


    WebM is an audiovisual media file format. It is primarily intended to offer a royalty-free alternative to use in the HTML5 video and the HTML5 audio elements. It has a sister project WebP for images. The development of the format is sponsored by Google, and the corresponding software is distributed under a BSD license.

    BSD licenses

    BSD licenses are a family of permissive free software licenses, imposing minimal restrictions on the use and distribution of covered software. This is in contrast to copyleft licenses, which have share-alike requirements. The original BSD license was used for its namesake, the Berkeley Software Distribution (BSD), a Unix-like operating system. The original version has since been revised, and its descendants are referred to as modified BSD licenses.

    ICC profile

    An ICC profile is a set of data that characterizes a color input or output device, or a color space, according to standards promulgated by the International Color Consortium (ICC). Profiles describe the color attributes of a particular device or viewing requirement by defining a mapping between the device source or target color space and a profile connection space (PCS). Mappings may be specified using tables, to which interpolation is applied, or through a series of parameters for transformations.

    Extensible Metadata Platform

    Extensible Metadata Platform (XMP) is an ISO standard, originally created by Adobe Systems Inc. for the creation, processing and interchange of standardized and custom metadata for digital documents and data sets.

    Open standard

    An open standard is a standard that is publicly available and has various rights to use associated with it, and may also have various properties of how it was designed (e.g. open process). There is no single definition and interpretations vary with usage.

    Portable Network Graphics

    Portable Network Graphics is a raster-graphics file-format that supports lossless data compression. PNG was developed as an improved, non-patented replacement for Graphics Interchange Format (GIF).


    pngcrush is a free and open-source command-line utility for optimizing PNG image files. It reduces the size of the file losslessly – that is, the resulting \"crushed\" image will have the same quality as the source image.


    PNGOUT is a freeware command line optimizer for PNG images written by Ken Silverman. The transformation is lossless, meaning that the resulting image is visually identical to the source image. According to its author, this program can often get higher compression than other optimizers by 5–10%. It is possible to compress some inflated PNGs to a size below 1% of the original file.

    Video coding format

    A video coding format (or sometimes video compression format) is a content representation format for storage or transmission of digital video content (such as in a data file or bitstream). Examples of video coding formats include H.262 (MPEG-2 Part 2), MPEG-4 Part 2, H.264 (MPEG-4 Part 10), HEVC (H.265), Theora, RealVideo RV40, VP9, and AV1.

    Image File Formats

    Image file formats are standardized means of organizing and storing digital images. Image files are composed of digital data in one of these formats that can be rasterized for use on a computer display or printer. An image file format may store data in uncompressed, compressed, or vector formats. Once rasterized, an image becomes a grid of pixels, each of which has a number of bits to designate its color equal to the color depth of the device displaying it.

    Raster graphics

    In computer graphics, raster graphics or bitmap image is a dot matrix data structure that represents a generally rectangular grid of pixels (points of colour), viewable via a monitor, paper, or other display medium. Raster images are stored in image files with varying formats.


    In digital imaging, a pixel, pel, or picture element is a physical point in a raster image, or the smallest addressable element in an all points addressable display device; so it is the smallest controllable element of a picture represented on the screen.

    Color depth

    Color depth or colour depth, also known as bit depth, is either the number of bits used to indicate the color of a single pixel, in a bitmapped image or video framebuffer, or the number of bits used for each color component of a single pixel.

    Optical character recognition(OCR)

    Optical character recognition or optical character reader (OCR) is the mechanical or electronic conversion of images of typed, handwritten or printed text into machine-encoded text, whether from a scanned document, a photo of a document, a scene-photo (for example the text on signs and billboards in a landscape photo) or from subtitle text superimposed on an image (for example from a television broadcast).

    Color space

    A color space is a specific organization of colors. In combination with physical device profiling, it allows for reproducible representations of color, in both analog and digital representations.

    Color model

    A color model is an abstract mathematical model describing the way colors can be represented as tuples of numbers, typically as three or four values or color components.

    Page description language (PDL)

    A page description language (PDL) is a computer language that describes the appearance of a printed page in a higher level than an actual output bitmap.

    Graphics Device Interface (GDI)

    The Graphics Device Interface (GDI) is a Microsoft Windows application programming interface and core operating system component responsible for representing graphical objects and transmitting them to output devices such as monitors and printers.


    a palette is a finite set of colors. Palettes can be optimized to improve image accuracy in the presence of software or hardware constraints.

    Routing information base (RIB)

    a routing table, or routing information base (RIB), is a data table stored in a router or a network host that lists the routes to particular network destinations, and in some cases, metrics (distances) associated with those routes.

    Static routing

    Static routing is a form of routing that occurs when a router uses a manually-configured routing entry, rather than information from a dynamic routing traffic. In many cases, static routes are manually configured by a network administrator by adding in entries into a routing table, though this may not always be the case.

    Reverse-path forwarding (RPF)

    Reverse-path forwarding (RPF) is a technique used in modern routers for the purposes of ensuring loop-free forwarding of multicast packets in multicast routing and to help prevent IP address spoofing in unicast routing.

    Routing loop

    A routing loop is a common problem with various types of networks, particularly computer networks. They are formed when an error occurs in the operation of the routing algorithm, and as a result, in a group of nodes, the path to a particular destination forms a loop.

    Packet shaping

    Traffic shaping, also known as \"packet shaping\" is the practice of regulating network data transfer to assure a certain level of performance, quality of service (QoS) or return on investment (ROI). The practice involves delaying the flow of packets that have been designated as less important or less desired than those of prioritized traffic streams. This technique is used by specifying what traffic at what rate (rate limiting) in a span of time (bandwidth throttling) you are going to allow in or out of your network.

    Bandwidth throttling

    Bandwidth throttling is the intentional slowing or speeding of an internet service by an Internet service provider (ISP). It is a reactive measure employed in communication networks to regulate network traffic and minimize bandwidth congestion. Bandwidth throttling can occur at different locations on the network. On a local area network (LAN), a system administrator (\"sysadmin\") may employ bandwidth throttling to help limit network congestion and server crashes. On a broader level, the Internet service provider may use bandwidth throttling to help reduce a user\'s usage of bandwidth that is supplied to the local network. Bandwidth throttling is also used to speed up the Internet on speed test websites.

    Area border router (ABR)

    An area border router (ABR) is a kind of router that is located near the border between one or more Open Shortest Path First (OSPF) areas. It is used to establish a connection between backbone networks and the OSPF areas. It is a member of both the main backbone network and the specific areas to which it connects, so it stores and maintains separate routing information or routing tables regarding the backbone and the topologies of the area to which it is connected.

    Traffic policing

    In communications, traffic policing is the process of monitoring network traffic for compliance with a traffic contract and taking steps to enforce that contract. Traffic sources which are aware of a traffic contract may apply traffic shaping to ensure their output stays within the contract and is thus not discarded. Traffic exceeding a traffic contract may be discarded immediately, marked as non-compliant, or left as-is, depending on administrative policy and the characteristics of the excess traffic.

    Traffic contract

    A traffic contract is a request forwarded to a network by a service that is willing to use an ATM network and wants to transmit data traffic over that ATM network. This request contains all information regarding the type of data and information that is to be transmitted, required network services and resources, bandwidth allocation and other related elements. All the above information is encapsulated within a request that is sent by a service to the network.

    High availability

    High availability is a system design protocol, which once implemented assures a specific degree of uptime continuity in a specific period of time.

    Cache engine

    A cache server is a dedicated network server or service acting as a server that saves Web pages or other Internet content locally. By placing previously requested information in temporary storage, or cache, a cache server both speeds up access to data and reduces demand on an enterprise\'s bandwidth. Cache servers also allow users to access content offline, including rich media files or other documents. A cache server is sometimes called a \"cache engine.\"

    Fault tolerance

    Fault tolerance is the way in which an operating system (OS) responds to a hardware or software failure. The term essentially refers to a system’s ability to allow for failures or malfunctions, and this ability may be provided by software, hardware or a combination of both. To handle faults gracefully, some computer systems have two or more duplicate systems.

    Dropped Packets

    Dropped packet or Packet loss occurs when one or more packets of data travelling across a computer network fail to reach their destination. Packet loss is either caused by errors in data transmission, typically across wireless networks, or network congestion. Packet loss is measured as a percentage of packets lost with respect to packets sent.


    When there are delays in transit, some packets leaving after others might arrive at the destination first. This variation in packet delay is called “jitter.” Applications like Voice over IP (VoIP) cannot be used effectively if jitter is excessive.

    Resource Reservation Protocol (RSVP)

    Resource Reservation Protocol (RSVP) is a transport layer protocol used to reserve network resources and enable running Internet applications to gain quality of service (QoS). Some old networks were required to provide reliability of data. However, in today\'s era of network systems, time is often more important than reliability. Instead, RSVP is supported by a QoS network, providing both the quality of service and insured data.

    Multiprotocol label switching (MPLS)

    Multiprotocol label switching (MPLS) is a mechanism used within computer network infrastructures to speed up the time it takes a data packet to flow from one node to another. It enables computer networks to be faster and easier to manage by using short path labels instead of long network addresses for routing network packets.

    Differentiated Services (DiffServ, or DS)

    Differentiated Services (DiffServ, or DS) is a protocol for specifying and controlling network traffic by class so that certain types of traffic get precedence - for example, voice traffic, which requires a relatively uninterrupted flow of data, might get precedence over other kinds of traffic.

    Integrated services or IntServ

    In computer networking, IntServ or integrated services is an architecture that specifies the elements to guarantee quality of service (QoS) on networks. IntServ can for example be used to allow video and sound to reach the receiver without interruption. IntServ specifies a fine-grained QoS system, which is often contrasted with DiffServ\'s coarse-grained control system.

    PCI Express(PCI-E)

    Peripheral Component Interconnect Express, better known as PCI Express (and abbreviated PCIe or PCI-E) and is a computer expansion card standard. PCI-E is used in motherboard-level connections and as an expansion card interface. The new standard for personal computers is called PCIe 3.0. One of the improvements of PCI-E over its predecessors is a new topology allowing for the faster exchange of data.


    A kernel is the core component of an operating system. Using interprocess communication and system calls, it acts as a bridge between applications and data processing performed at the hardware level. When an operating system is loaded into memory, the kernel loads first and remains in memory until the operating system is shut down again. The kernel is responsible for low-level tasks such as disk management, task management and memory management.

    Thread block

    A thread block is a programming abstraction that represents a group of threads that can be executed serially or in parallel. For better process and data mapping, threads are grouped into thread blocks. The number of threads varies with available shared memory.

    CUDA (Compute Unified Device Architecture)

    CUDA (Compute Unified Device Architecture) is a parallel computing platform and application programming interface (API) model created by Nvidia. It allows software developers and software engineers to use a CUDA-enabled graphics processing unit (GPU) for general purpose processing — an approach termed GPGPU (General-Purpose computing on Graphics Processing Units). The CUDA platform is a software layer that gives direct access to the GPU\'s virtual instruction set and parallel computational elements, for the execution of compute kernels.

    Configuration files

    In computer science, configuration files provide the parameters and initial settings for the operating system and some computer applications. Configuration files are usually written in ASCII encoding and contain all necessary data about the specific application, computer, user or file. Configuration files can be used for a wide range of reasons, though they are mostly used by operating systems and applications to customize the environment. Configuration files are used for operation system settings, server processes or software applications. Configuration files are also known as config files.

    Distributed computing

    Distributed computing is a computing concept that, in its most general sense, refers to multiple computer systems working on a single problem. In distributed computing, a single problem is divided into many parts, and each part is solved by different computers. As long as the computers are networked, they can communicate with each other to solve the problem. If done properly, the computers perform like a single entity. The ultimate goal of distributed computing is to maximize performance by connecting users and IT resources in a cost-effective, transparent and reliable manner. It also ensures fault tolerance and enables resource accessibility in the event that one of the components fails.


    A loader is a major component of an operating system that ensures all necessary programs and libraries are loaded, which is essential during the startup phase of running a program. It places the libraries and programs into the main memory in order to prepare them for execution. Loading involves reading the contents of the executable file that contains the instructions of the program and then doing other preparatory tasks that are required in order to prepare the executable for running, all of which takes anywhere from a few seconds to minutes depending on the size of the program that needs to run.

    Power-on self-test (POST)

    A power-on self-test (POST) is a succession of built-in diagnostic tests performed when turning on a computer. This series of tests determines the proper functioning of the following: Random access memory (RAM) Disk drives Hard drives Central processing unit (CPU) All other hardware devices

    Boot loader

    A boot loader is a type of program that loads and starts the boot time tasks and processes of an operating system or the computer system. It enables loading the operating system within the computer memory when a computer is started or booted up. A boot loader is also known as a boot manager or bootstrap loader.

    Legacy system

    A legacy system, in the context of computing, refers to outdated computer systems, programming languages or application software that are used instead of available upgraded versions. Legacy systems also may be associated with terminology or processes that are no longer applicable to current contexts or content, thus creating confusion. In theory, it would be great to be able to have immediate access to use the most advanced technology. But in reality, most organizations have legacy systems - to some extent. A legacy system may be problematic, due to compatibility issues, obsoletion or lack of security support. A legacy system is also known as a legacy platform.

    memory bus

    The memory bus is a type of computer bus, usually in the form of a set of wires or conductors which connects electrical components and allow transfers of data and addresses from the main memory to the central processing unit (CPU) or a memory controller. It is part of a PC’s collection of transport buses that are used for high-speed data channeling and transferring of information to and from certain parts of the system. To reduce time delays, newly-designed memory buses are made to directly connect to dynamic random access memory (DRAM) chips instead of passing through different controllers.

    system bus

    The system bus is a pathway composed of cables and connectors used to carry data between a computer microprocessor and the main memory. The bus provides a communication path for the data and control signals moving between the major components of the computer system. The system bus works by combining the functions of the three main buses: namely, the data, address and control buses. Each of the three buses has its separate characteristics and responsibilities.

    address bus

    An address bus is a computer bus architecture used to transfer data between devices that are identified by the hardware address of the physical memory (the physical address), which is stored in the form of binary numbers to enable the data bus to access memory storage. The address bus is used by the CPU or a direct memory access (DMA) enabled device to locate the physical address to communicate read/write commands. All address busses are read and written by the CPU or DMA in the form of bits.

    Pixel pipelines

    Pixel pipelines are graphics card components that process pixel information and are dedicated to accelerate image processing tasks. They have a reprogrammable processing core plus two independent frame buffers that are used to temporarily store image data and can operate on pixel data up to 200MB/s rates. Pixel pipelines are comprised of pixel shaders and texture management units (TMU). If a graphics card has 24 pixel shaders and 24 TMUs, then that card is said to have 24 pixel pipelines. But it is not always a one-to-one ratio as some cards have more TMUs than shaders. Pixel pipelines are also known as pixel processors.

    Bypass airflow

    Bypass airflow refers to a conditioned air leak that prevents properly conditioned air (usually cooled or temperature controlled air) from reaching specific computer parts. Leaking air may escape through cabling holes, under cabinets in ceilings or through wall openings or holes.

    Equipment footprint

    Equipment footprint refers to the physical space a computing device or equipment requires when being placed or deployed within a home, office or computing facility. It is generally equated in terms of size in square feet / meters of area that the device will consume in a physical location and its impact on the overall space.

    In-row cooling

    In-row cooling technology is a type of air conditioning system commonly used in data centers in which the cooling unit is placed between the server cabinets in a row for offering cool air to the server equipment more effectively. In-row cooling systems use a horizontal airflow pattern utilizing hot aisle/cold aisle configurations and they only occupy one-half rack of row space without any additional side clearance space. Typically, each unit is about 12 inches wide by 42 inches deep. These units may be a supplement to raised-floor cooling (creating a plenum to distribute conditioned air) or may be the primary cooling source on a slab floor.

    raised floor

    A raised floor is a type of elevated structural floor that is supported by a metal grid and allows cables, mechanical facilities, electrical supplies and wiring to run beneath it. It is generally used in data centers, telecommunication environments, military command centers and modern office buildings. Sometimes there is additional structural support and lighting that allows for a crawl space or walkway underneath. A raised floor is also a common way to cool a building by using the empty space beneath the raised floor as a plenum chamber to dispense conditioned air. A raised floor may also be referred to as raised flooring, an access floor, access flooring and a raised access computer floor.

    server cage

    A server cage is a specific kind of container for physical server hardware. Like the traditional cage, server cages have open systems composed of metal bars or similar structures, where light and air can move through the enclosure, but where the cage provides effective security for what\'s inside.

    Internet radio appliance

    An internet radio appliance is a hardware innovation that functions very much like a radio when connected to the internet. It was born due to emerging web-based music services like Apple’s iTunes and other online radio broadcasting stations available for PC and mobile users that stream music. This is a smaller and more dedicated device that remains connected and plays/streams continuously, versus using a laptop or PC to listen to Internet radio. An internet radio appliance is also known as a web radio.

    control bus

    A control bus is a computer bus that is used by the CPU to communicate with devices that are contained within the computer. This occurs through physical connections such as cables or printed circuits. The CPU transmits a variety of control signals to components and devices to transmit control signals to the CPU using the control bus. One of the main objectives of a bus is to minimize the lines that are needed for communication. An individual bus permits communication between devices using one data channel. The control bus is bidirectional and assists the CPU in synchronizing control signals to internal devices and external components. It is comprised of interrupt lines, byte enable lines, read/write signals and status lines.

    peripheral device

    A peripheral device is an internal or external device that connects directly to a computer but does not contribute to the computer\'s primary function, such as computing. It helps end users access and use the functionalities of a computer.


    In its most basic sense, memory refers to any information or data, often in binary format, that a machine or technology can recall and use. There are many different kinds of memory in conventional computers and other devices, and they differ based on the complex design of the hardware in which they\'re stored. As new devices continue to emerge to complement traditional desktop and laptop computers, the ways that devices use memory may become more complex. It’s critical for users and buyers to understand each type of memory, and how they are used, in order to make good buying decisions.

    memory address

    A memory address is a unique identifier used by a device or CPU for data tracking. This binary address is defined by an ordered and finite sequence allowing the CPU to track the location of each memory byte. Modern computers are addressed by bytes which are assigned to memory addresses – binary numbers assigned to a random access memory (RAM) cell that holds up to one byte. Data greater than one byte is consecutively segmented into multiple bytes with a series of corresponding addresses. Hardware devices and CPUs track stored data by accessing memory addresses via data buses. Before CPU processing, data and programs must be stored in unique memory address locations.

    dual inline memory module (DIMM)

    A dual inline memory module (DIMM) is a small-scale circuit board that holds memory chips on the motherboard. DIMM incorporates a series of memory called dynamic random access memory (DRAM), which provides primary storage, the main memory that continually reads and executes stored instructions or data directly to the CPU. DIMM is an attempt to improve on the earlier single inline memory module (SIMM), which used matched pairs. DIMM uses only one circuit board, thus increasing memory speed and storage. DIMM also has a much smaller circuit board and easier insertion compared to SIMM.

    Central processing unit cache (CPU cache)

    Central processing unit cache (CPU cache) is a type of cache memory that a computer processor uses to access data and programs much more quickly than through host memory or random access memory (RAM). It enables storing and providing access to frequently used programs and data. CPU cache is also known as processor cache.

    Core memory

    Core memory was a common form of random access memory (RAM) from the mid-1950s to the mid-\'70s, and It was developed at MIT in 1951. The memory made use of magnetic rings called cores that had wires passing through them for selecting and detecting the contents of the cores. With the introduction of memory based on semiconductor technology, core memory became obsolete, though some still call the main memory of a computer, the core memory. Core memory is also known as magnetic-core memory.

    program counter (PC)

    A program counter (PC) is a CPU register in the computer processor which has the address of the next instruction to be executed from memory. It is a digital counter needed for faster execution of tasks as well as for tracking the current execution point. A program counter is also known as an instruction counter, instruction pointer, instruction address register or sequence control register.

    Read-only memory (ROM)

    Read-only memory (ROM) is a type of storage medium that permanently stores data on personal computers (PCs) and other electronic devices. It contains the programming needed to start a PC, which is essential for boot-up; it performs major input/output tasks and holds programs or software instructions. Because ROM is read-only, it cannot be changed; it is permanent and non-volatile, meaning it also holds its memory even when power is removed. By contrast, random access memory (RAM) is volatile; it is lost when power is removed. (start from here) There are numerous ROM chips located on the motherboard and a few on expansion boards. The chips are essential for the basic input/output system (BIOS), boot up, reading and writing to peripheral devices, basic data management and the software for basic processes for certain utilities.

    Non-volatile memory (NVM)

    Non-volatile memory (NVM) is a type of computer memory that has the capability to hold saved data even if the power is turned off. Unlike volatile memory, NVM does not require its memory data to be periodically refreshed. It is commonly used for secondary storage or long-term consistent storage. Non-volatile memory is highly popular among digital media; it is widely used in memory chips for USB memory sticks and digital cameras. Non-volatile memory eradicates the need for relatively slow types of secondary storage systems, including hard disks. Non-volatile memory is also known as non-volatile storage.

    Basic input/output system (BIOS)

    A basic input/output system (BIOS) is a pre installed program used during startup on Windows-based computers. The CPU initially accesses the BIOS, after which the operating system is loaded. A basic input/output system is also known as system BIOS or ROM BIOS.

    Programmable Read-Only Memory (PROM)

    Electrically Erasable Programmable Read-Only Memory (EEPROM)

    Electrically Erasable Programmable Read-Only Memory (EEPROM) is a stable, non-volatile memory storage system that is used for storing minimal data quantities in computer and electronic systems and devices, such as circuit boards. This data may be stored, even without a permanent power source, as device configuration or calibration tables.If storing higher volumes of data that is static (like in USB drives), certain types of EEPROM (like flash memory) are more cost-effective than conventional EEPROM devices.

    expanded memory specification (EMS)

    An expanded memory specification (EMS) was a technique introduced in about 1984 for expanding the conventional or main memory beyond 1 MB in IBM XT compatible computers. The process was known as bank switching and involved expanding memory beyond that which was directly addressed by the processor. EMS was designed for disk operating system (DOS) software programs requiring the additional memory. EMS is also known as expanded memory, LIM EMS, LIM 4.0 or EMS 4.0.


    Firmware is a software program permanently etched into a hardware device such as keyboards, hard drive, BIOS, or video cards. It is programmed to give permanent instructions to communicate with other devices and perform functions like basic input/output tasks. Firmware is typically stored in the flash ROM (read only memory) of a hardware device. It can be erased and rewritten. Firmware was originally designed for high level software and could be changed without having to exchange the hardware for a newer device. Firmware also retains the basic instructions for hardware devices that make them operative. Without firmware, a hardware device would be non-functional.

    Read-write memory (RWM)

    Read-write memory (RWM) is computer memory that can be read from and written to. This type of memory can be contrasted with read-only memory, which cannot be modified after it is written. Both of these contrast with another, more obscure, type of memory called write-only memory, which is very narrowly applied to hardware setups. Having read-write memory design makes devices much more valuable to users, and adds more functionality to technologies.

    Write-only memory (WOM)

    Write-only memory describes memory locations that cannot be read, but can only be written to. In some senses, this term is a logical fallacy in IT, but it does have some relevance to certain systems involved in the interaction between microprocessors and some kinds of hardware.

    Device driver

    A device driver is a particular form of software application that is designed to enable interaction with hardware devices. Without the required device driver, the corresponding hardware device fails to work. A device driver usually communicates with the hardware by means of the communications subsystem or computer bus to which the hardware is connected. Device drivers are operating system-specific and hardware-dependent. A device driver acts as a translator between the hardware device and the programs or operating systems that use it. A device driver may also be called a software driver.

    Boot sector

    A boot sector is a reserved sector of a disk or storage device that contains the necessary data or code used to complete the boot process of a computer or disk. A boot sector is also known as a boot block.

    Extended system configuration data (ESCD)

    Extended system configuration data (ESCD) is a portion of the nonvolatile basic input/output system (BIOS) memory (also known as complementary metal-oxide-semiconductor (CMOS) memory) on a personal computer motherboard. This is also where the ISA PnP device data is located. ESCD is employed by the BIOS to assign resources for hardware extensions, commonly called expansion cards.

    Beep code

    A beep code is a type of signal provided by a personal computer during the boot process. Most beep codes are related to a power on self test (POST), where a beep code helps show end-users that there is a hardware problem preventing normal operation.

    Boot sequence

    Boot sequence is the order in which a computer searches for nonvolatile data storage devices containing program code to load the operating system (OS). Typically, a Macintosh structure uses ROM and Windows uses BIOS to start the boot sequence. Once the instructions are found, the CPU takes control and loads the OS into system memory. The devices that are usually listed as boot order options in the BIOS settings are hard disks, floppy drives, optical drives, flash drives, etc. The user is able to change the boot sequence via the CMOS setup. Boot sequence is also called as boot order or BIOS boot order.

    Master boot record (MBR)

    The master boot record is a category of boot sector and the very first sector found in computer mass storage media such as fixed disks and removable computer drives. The master boot record provides the information on loading the operating system and also on the partition of the hard disk. The programs residing in master boot record help determine which partition needs to be used while booting. The master boot record is absent on non-partitioned devices such as super floppies, floppies or other devices configured in such a manner.

    Volume boot record (VBR)

    A volume boot record (VBR) is the first sector in a data storage device that is not partitioned or the first sector in a partition of a data storage device that itself has undergone partition. Volume boot records often contain the computer code to initiate the boot process, or the code for loading and invoking a standalone program or operating system installed on the device or on the partition. A volume boot record is also known as a partition boot sector or volume boot sector.

    Boot sector virus

    A boot sector virus is a computer virus that infects a storage device\'s master boot record (MBR). It is not mandatory that a boot sector virus successfully boot the victim\'s PC to infect it. As a result, even non-bootable media can trigger the spread of boot sector viruses. These viruses copy their infected code either to the floppy disk\'s boot sector or to the hard disk\'s partition table. During start-up, the virus gets loaded to the computer\'s memory. As soon as the virus is saved to the memory, it infects the non-infected disks used by the system. The propagation of boot sector viruses has become very rare since the decline of floppy disks. Also, present-day operating systems include boot-sector safeguards that make it difficult for boot sector viruses to infect them.

    Banker Trojan

    A banker Trojan is a piece of malware intended to get financial information or hack users through a banking or financial system, commonly through an online banking or brokerage interface.


    Binder is an open logic based security language. It encodes security statements, making them components of distributed logic programs to express security statements in a distributed system.

    Blended threat

    A blended threat is a type of exploit that uses multiple techniques to attack a system. The definition is broad, but this generally means propogating in multiple ways as well as attempting to use multiple vulnerabilities in the target system.

    Blind drop

    A blind drop is a hidden location where a malware program, Trojan or virus drops information gathered from a host. The automatically gathered data remains in that location until it is retrieved by the attacker. The data could be a credit card or bank account details, usernames and passwords or any personal information the attacker may use to hack into the host\'s accounts. It is very hard to detect where data is coming from or where it is going, even if the location is discovered.

    Non-Volatile Random Access Memory (NVRAM)

    Non-Volatile Random Access Memory (NVRAM) is a category of Random Access Memory (RAM) that retains stored data even if the power is switched off. NVRAM uses a tiny 24-pin dual inline package (DIP) integrated circuit chip, which helps it to gain the power required to function from the CMOS battery on the motherboard. NVRAM monitors several system parameters, such as Ethernet the MAC address, serial number, date of manufacture, HOSTID, etc. Therefore, NVRAM is a non-volatile memory type that provides the random access facility.


    A MIDlet is an application that uses the mobile information device profile (MIDP) for the Java Platform, Micro Edition (Java ME) environment. When Java was the most widely used mobile platform, the MIDlet became the most ubiquitous of mobile applications. In fact, MIDlets still exist in a majority of low-end feature phones.

    Mobile Internet Device (MID)

    A Mobile Internet Device (MID) is a small multimedia-enabled mobile device that provides wireless Internet access. MIDs facilitate real-time and two-way communication by filling the multimedia gap between mobile phones and tablets. A MID is larger than a handheld device, like a smartphone, but smaller than an ultra-mobile PC (UMPC). MID technology focuses on providing entertainment, information and location-based services to individual consumers, rather than enterprises.

    Joint application development (JAD)

    Joint application development (JAD) is a prototyping life cycle methodology that uses collaborative JAD workshops to depict the business viewpoint of end users (or customers) for effective solution development. In project development, the historical approach involves individual stakeholder interviews, which may not yield appropriate required output. JAD team workshops are geared toward summarizing and resolving development issues through a joint effort between developers and end users.

    Enterprise resource planning (ERP)

    Enterprise resource planning (ERP) is a method of efficiently utilizing people, hardware and software to increase productivity and profit, thus simplifying a company’s business processes. ERP may include many software applications or a single (but more complex) software package that smoothly disseminates data required by two or more unique business departments.

    Rapid application development (RAD)

    Rapid application development (RAD) is a suite of software development methodology techniques used to expedite software application development. RAD uses predefined prototyping techniques and tools to produce software applications. It encompasses a graphical user interface (GUI) development environment, allowing end users to easily drag and drop required software application components. Software RAD techniques employ computer-aided software engineering (CASE).

    Ensemble programming

    Ensemble programming refers to the programming techniques and tools which are used for an integrated application development that is capable of transcending various interfaces and devices. It combines the advanced technologies of mobile application development (AD) and Web development to create user interfaces that can provide a seamless and high-quality user experience that is not limited to a single device. Designers employ various techniques and tools to make ensemble programming work and must take into consideration the various factors involved for providing such a uniform user experience.

    Network Based Application Recognition (NBAR)

    Network Based Application Recognition (NBAR) intelligently identifies, classifies and regulates bandwidth for mission critical applications, including enterprise resource planning (ERP) and workforce optimization applications to ensure the efficient use of resources. NBAR was developed by Cisco as part of its content networking platform for implementing intelligent network (IN) services. Even non-critical applications, such as Internet gaming and MP3 file sharing, can be classified, marked, policed or blocked by NBAR.

    Architected rapid application development (ARAD)

    Architected rapid application development (ARAD) refers to software that uses frameworks and patterns as main elements to aid in the development of common functions of an application. ARAD is an advanced form of object-oriented analysis and design tools. It involves the use of design patterns and analysis of already created models. Organizations are widely using ARAD along with agile methodologies and practices.

    Rapid mobile application development (RMAD)

    Rapid mobile application development (RMAD) is a specific type of rapid application development (RAD) that affects mobile designs. It is based on the idea that application development can be expedited with various streamlining approaches.

    Access modifiers

    Access modifiers are keywords used to specify the accessibility of a class (or type) and its members. These modifiers can be used from code inside or outside the current application.

    Mobile computing device

    A mobile computing device is any device that is created using mobile components, such as mobile hardware and software. Mobile computing devices are portable devices capable of operating, executing and providing services and applications like a typical computing device. Mobile computing devices also may be known as portable computing devices or handheld computing devices.

    Ultra Mobile PC (UMPC)

    Ultra Mobile PC (UMPC) is a small handheld computer with the capacity to run the Windows operating system (OS). Although it is closer to the size of a palmtop than a laptop, an Ultra Mobile PC provides more functionality than a palmtop.

    Perfect RAM

    Perfect RAM is a type of non-volatile random access memory. It stores data by changing the state of the material used; chalcogenide glass switches between states when it is subjected to the heat produced by the passage of an electric current. On a microscopic level, the data changes back and forth between two states: amorphous and crystalline. Perfect RAM is one of several memory technologies competing to replace flash memory, which has a number of problems. This term is also known as PRAM, PCRAM, Ovonic Unified Memory, Chalcogenide RAM, C-RAM, and Phase-Change Memory (PCM).

    Personal Identifiable Information (PII or pii)

    Personal Identifiable Information (PII or pii) is a type of data that identifies the unique identity of an individual. It is one of the most basic forms of personal information and includes an individual’s name, gender, address, telephone, email address or basic biometric data information that is electronically stored within a device or application.

    Browser modifier

    A browser modifier is a type of malware created for the sole purpose of hijacking and modifying a Web browser’s settings. Browser modifiers are installed when users inadvertently click pop-up messages without reading the content that explains how to cancel the pop-up. This term is also known as a browser hijacker, although the latter may refer to malware with more malicious, rather than mischievous, intentions.

    Trojan horse

    A Trojan horse is a seemingly benign program that when activated, causes harm to a computer system. A Trojan horse is also known as a Trojan virus or Trojan. One of the most insidious types of Trojan horse is a program that claims to rid your computer of viruses but instead introduces viruses onto your computer.

    Malicious software

    Malicious software, commonly known as malware, is any software that brings harm to a computer system. Malware can be in the form of worms, viruses, trojans, spyware, adware and rootkits, etc.which steal protected data, delete documents or add software not approved by a user.

    Clickjack attack

    A clickjack attack is a malicious technique used by an attacker to record the infected user’s clicks on the Internet. This can be used to direct traffic to a specific site or to make a user like or accept a Facebook application. More nefarious purposes might be to collect sensitive information saved on a browser, such as passwords, or to install malicious content. This type of attack is also known as clickjacking or UI readdressing.

    Unified threat management (UTM)

    Unified threat management (UTM) refers to a specific kind of IT product that combines several key elements of network security to offer a comprehensive security package to buyers. A unified threat management solution involves combining the utility of a firewall with other guards against unauthorized network traffic along with various filters and network maintenance tools, such as anti-virus programs.

    Integrated threat management (ITM)

    As the name implies, ITM represents a unified solution that runs between a corporate/other network and public access channel. An effective ITM solution incorporates firewalls, virtual private networks (VPN), antivirus capabilities and other security measures to protect a network at various levels. ITM solutions address different types of attacks, such as malware and spam. Developers consider the broad range of attacks that result in system damage - from crashing systems to damaging or stealing data. An effective ITM tool addresses the most common system threats in a production environment.

    Zero-day threat

    A zero-day threat is a threat that exploits an unknown computer security vulnerability. The term is derived from the age of the exploit, which takes place before or on the first (or “zeroth”) day of a developer’s awareness of the exploit or bug. This means that there is no known security fix because developers are oblivious to the vulnerability or threat. Attackers exploit zero-day vulnerabilities through different vectors. Web browsers are the most common, due to their popularity. Attackers also send emails with attachments exploiting software attachment vulnerabilities. A zero-day threat is also known as a zero-hour attack or day-zero attack.


    Bugbear is a 2002 virus that has been responsible for thousands of cases of virus hacking that involve exploiting Microsoft Outlook and Outlook Express to install a keylogger on personal and business computers. This is one of several similar viruses that enters the computer through an attachment to an email. Bugbear is also known as Tanatos.

    Access control list (ACL)

    Access control list (ACL) refers to the permissions attached to an object that specify which users are granted access to that object and the operations it is allowed to perform. Each entry in an access control list specifies the subject and an associated operation that is permitted.


    A delegate is an object-oriented, managed, secure and type-safe function pointer in the .NET framework. A delegate signature includes its name, return type and arguments passed to it. Rather than passing data, a delegate passes a method to another method. Delegates are used in many contexts, including implementing callbacks and event handlers, entry thread points and multiple types of method specifications. Because a delegate does not know the class of a referenced object, it is used for anonymous invocation.

    interrupt request (IRQ)

    An interrupt request (IRQ) is an asynchronous signal sent from a device to a processor indicating that in order to process a request, attention is required. A hardware IRQ is induced by a hardware peripheral or device request, whereas a software IRQ is induced by a software instruction. Both result in processor status savings, and revert to serving the IRQ using an interrupt handler routine.

    Industry Standard Architecture (ISA)

    Industry Standard Architecture (ISA) is a computer bus specification used for 8-bit IBM-compatible systems. An ISA bus provides a basic route for peripheral devices that are attached to a motherboard to communicate with different circuits or other devices that are also attached to the same motherboard. Peripheral component interface (PCI) started replacing the ISA bus in the mid-\'90s. New motherboards were manufactured with fewer ISA slots, and preference was given to PCI slots.

    Plug and Play (PnP)

    Plug and Play (PnP) is a technology that allows the operating system to detect and configure internal and external peripherals as well as most adapters. It has the ability to find and configure hardware components without having to reset DIP switches and jumpers. PnP also refers to hot swapping, or hot plugging, structures such as Firewire or USB sticks and other devices. When booting a PC, PnP identifies the attached peripheral devices and regulates the proper internal settings by configuring the direct memory access (DMA), interrupt requests (IRQ) and input/output (I/O) addresses.

    Device manager

    The device manager is a Control Panel applet within Windows operating systems since its introduction with Windows 95. It is used to view and manage all the hardware devices installed on a computer, such as hard drives, sound cards, USB devices, keyboards, and so on.

    Certified Output Protection Protocol (COPP)

    Certified Output Protection Protocol (COPP) is a device driver technology that uses logo identification to deny access to video outputs or recordings. It was developed to prevent unauthorized digital video applications through developed security technology. Microsoft has encrypted control signals to ensure this type of protection. There are three protection mechanisms, and any graphics adapter must support one of them. This protocol securely connects between the graphics driver and the communication channel. The primary purpose of this security measure is to block unauthorized users from streaming protected audio and video.

    File Compression

    File compression is a data compression method in which the logical size of a files is reduced to save disk space for easier and faster transmission over a network or the internet. It also Known as File Zipping.

    Lossy Compression

    A compression technique that does not decompress digital data back to 100% of the original. Lossy method can provide high degrees of compression and result in smaller compressed files, but some number of the original pixels, sound waves or video frames are removed forever.

    Vector Graphics

    The representation of a digital image as points, lines and other geometric entities. All computer-aided design (CAD), drawing and diagramming programs create vector images.

    Cloud Based

    Operations that involve a network. The term often refers to the public internet, however a cloud may also be a private, internal network.

    SSL (Secure Sockets Layer)

    An earlier security protocol that was the Internet standard prior to TLS. Developed by Netscape, SSL was widely used to validate the identity of a website and create an encrypted connection

    Hotlink Protection

    Hotlink Protection is an optional features to the LSN CDN that allows you to protect your bandwidth by disallowing other domains from linking to content you have on the CDN.

    404 Errors

    The HTTP 404 Not Found Error means that the webpage you were trying to reach could not be found on the server. It is a Client-side Error which means that either the page has been removed or moved and the URL was not changed accordingly, or that you typed in the URL incorrectly. Put simply, a 404 Not Found Error means that the webpage simply does not exist with the URL entered.

    Yslow Score

    YSlow is an open source project and tool that analyzes web pages and helps you figure out why they are slow based on Yahoo!’s rules for high performance websites.

    3rd Party Request

    Third Party request means a request from a third party for records relating to an end user’s use of the services.

    Webpage Testing

    Complete testing of web-based page system before going live can help address issues before the system is revealed to the public.


    It is a kind of Tool designed to help a website’s performance optimization.


    Pagelocity is a web page optimization application covering: social media, content marketing, resources and code analysis

    GT Matrix

    It is a website performance analytics tool, created by GT.net, who are well known in the digital space for the speed monitoring tool, Pingdom. The key objective of GTMetrix is to analyse the performance of your website and provide you with a list of actionable recommendations to improve it.

    FMP (First Meaningful Paint)

    is one of six metrics tracked in the performance section of the Lighthouse report. Each of these metrics captures some aspect of page load speed. The Lighthouse reports displays the FMP time period in seconds.

    CSS (Cascading Style Sheets)

    CSS describes how HTML elements are to be displayed on screen, paper, or in other media. It can control the layout of multiple web pages all at once. External stylesheets are stored in CSS files.

    VPS (Virtual Private Server)

    It is having a private operating system (OS) and the customers may have a superuser - level access to that operating system interface, so they can install almost any software that runs on that OS.


    It is the standard unit of measurement for the maximum number of reads and writes to non - contiguous storage location.


    It measures the time between issuing a request and receiving a response. With regards to IOPS, latency is a measure of the length of time it takes for a single i/o request to be completed from the applications point of view.

    Elapsed Time

    Elapsed time is measured by the time from the first moment of sending the data and the time of the last byte of the received response. Elapsed time – Latency time = Download Time

    Performance Thresholds

    Performance Thresholds are the KPIs or the maximum acceptable values of a metric . These are many metrics to be identified for a performance test project.

    Multivariate Testing

    Multivariate testing is a process by which more than one component of a website may be tested in a live environment. It can be thought of in simple terms as numerous A/B tests performed on one page at the same time.


    When used in the context of communication networks, such as Ethernet or packet radio, throughput or network throughput is the rate of successful message delivery over a communication channel. The data these messages belong to may be delivered over a physical or logical link, or it can pass through a certain network node.


    Time to first byte is a measurement used as an indication of the responsiveness of a web server or other network resource. TTFB measures the duration from the user or client making an HTTP request to the first byte of the page being received by the client\'s browser.

    SRC Set

    The srcset attribute specifies the URL of the image to use in different situations. This attribute is required when source is used in picture.

    Image Sprite

    An image sprite is a collection of images put into a single image. A web page with many images can take a long time to load and generates multiple server requests.


    It is scalable Vector Graphic. XML-based vector image format for two-dimensional graphics with support for interactivity and animation. The SVG specification is an open standard developed by the World Wide Web Consortium since 1999. SVG images and their behaviors are defined in XML text files

    Payload Computing

    A payload refers to the component of a computer virus that executes a malicious activity. Apart from the speed in which a virus spreads, the threat level of a virus is calculated by the damage it causes. Viruses with more powerful payloads tend to be more harmful.

    Log File

    A log file is a file that keeps a registry of events, processes, messages and communication between various communicating software applications and the operating system. Log files are present in executable software, operating systems and programs whereby all the messages and process details are recorded.

    Web Font Performance

    Web fonts are those not installed on a person’s computer, thereby having to load from a web server. They are downloaded by using the CSS3 declaration and must be supported by the web browser.

    Webpage Test

    Webpage Test is a web performance tool that uses real browsers to access web pages and collect timing metrics. The killer feature of WebPageTest is the metric called SpeedIndex, a measure of how fast the above-the-fold content is displayed.

    Page Speed

    Page Speed is the amount of time that it takes for a web page to load. A page\'s loading speed is determined by several different factors, including a site\'s server, page file size, and image compression.

    PWA (Progressive Web App)

    Progressive web applications (PWAs) are a type of application software delivered through the web, built using common web technologies including HTML, CSS and JavaScript. They are intended to work on any platform that uses a standards-compliant browser. Functionality includes working offline, push notifications, and device hardware access, enabling creating user experiences .


    The concept of accessible design and practice of accessible development ensures both direct access and indirect access meaning compatibility with a person\'s assistive technology. Accessibility can be viewed as the \"ability to access\" and benefit from some system or entity.

    First CPU Idle

    First CPU Idle is one of six metrics tracked in the performance section of the Lighthouse report. Each of these metrics captures some aspect of page load speed. The Lighthouse reports displays the First CPU Idle time period in seconds

    First Input Delay (FID)

    FID is a metric that tracks the delay between the time a user can attempt to interact with a part of the site, and the time that the interface is able to respond to that interaction.The FID metric is in some ways an intersection of the First Contentful Paint and Time to Interactive metrics.


    In a solvable linear optimization problem, a constraint is saturated if it is binding at a certain optimal solution and it is weakly saturated if it is binding at a proper subset of the optimal set. Non Saturation and weak saturation can be seen as redundancy phenomena in the sense that the elimination of a finite number of these constraints preserves the value of the given problem.


    A data center or data centre is a building, dedicated space within a building, or a group of buildings used to house computer systems and associated components, such as telecommunications and storage systems

    Feature Flags

    Feature flags are a software development technique that turns certain functionality on and off, without deploying new code. This allows for better control and more experimentation over the full lifecycle of features.The idea behind feature flags is to build conditional feature branches into code in order to make logic available only to certain groups of users at a time. If the flag is “on,” new code is executed, if the flag is “off,” the code is skipped.

    Feature Rollout

    A feature rollout is the software development process of introducing a new feature to a set of users. A feature rollout process involves planning, scheduling, controlling and testing a feature release through different stages and environments

    Lead Generation

    Lead generation is the process of generating consumer interest for a product or service with the goal of turning that interest into a sale. In online marketing this typically involves collecting a visitor’s contact information (called a “lead”) via a web form.

    Hero Image

    A hero image is a website design term used to describe an oversized banner image at the top of a website. Sometimes called a “hero header”, it serves as a user’s first glimpse of your company and offering because of its prominent placement towards the top of a webpage that usually extends full-width.

    Heat Map

    A heatmap is a graphical representation of data that uses a system of color-coding to represent different values. Heatmaps are used in various forms of analytics but are most commonly used to show user behaviour on specific webpages or web page templates. Heatmaps can be used to show where users have clicked on a page, how far they have scrolled down a page, or used to display the results of eye-tracking tests.

    Headline Testing

    Headline testing refers to the process of developing multiple title variations for an article or piece of online media, which can then be tested on multiple audience segments to determine which one performs the best.

    Growth Hacking

    Growth hacking is the use of resource-light and cost-effective digital marketing tactics to help grow and retain an active user base, sell products and gain exposure.

    Multi Armed Bandit

    A multi-armed bandit solution is a smarter or more complex version of A/B testing that uses machine learning algorithms to dynamically allocate traffic to variations that are performing well, while allocating less traffic to variations that are underperforming. In theory, multi-armed bandits should produce faster results since there is no need to wait for a single winning variation.

    Split Testing

    Split Testing is a method of conducting controlled, randomized experiments with the goal of improving a website metric, such as clicks, form completions, or purchases

    Squeeze Page

    A squeeze page is a landing page which is specifically designed to collect email addresses from visitors and potential customers. Squeeze pages are designed in such a way as to use incentives, scarcity, and other psychological tactics in order to “squeeze” a visitor into providing their email.

    Type 1 Error

    A Type 1 error (or type I error) is a statistics term used to refer to a type of error that is made in testing when a conclusive winner is declared although the test is actually inconclusive.

    Type 2 Error

    A type 2 error is a statistics term used to refer to a type of error that is made when no conclusive winner is declared between a control and a variation when there actually should be one.

    Viewable Impression

    A viewable impression is a standard measure of ad viewability defined by the International Advertising Bureau (IAB) to be an ad which appears at least 50% on screen for more than one second. Viewable impressions are the metric that advertisers use to quantify the percentage of ads that are actually viewed by real people.

    CTR (Click Through Rate)

    It is the percentage of clicks on a button or a link, out of the total number of visitors who saw it.

    Client Site Tasting

    Client-Side testing is concerned with the execution of code on the client, typically natively within a web browser or browser plugin. The execution of code on the client-side is distinct from executing on the server and returning the subsequent content.

    Data Layer

    The data layer is through the use of what is sometimes referred to as a Universal Data Object (UDO), which is written in the JavaScript programming language. The types of data contained in a data layer can be numerous and varied, consisting of things like e-commerce transaction information, web behavioral data, and mobile application usage. The graphic to the right shows a web channel broken down by components.

    Macro Conversion

    The term macro conversion describes the conversion of a website visitor into a paying customer or a subscriber of a web service. Macro conversions are usually defined as website goals, so that the success of a website can be measured using the conversion rates.

    Micro Conversion

    A micro conversion is any incremental step a user can take to show initial interest in your brand or product. It is Basically based on 2 categories Process Milestone Secondary Actions


    It is a website that promotes another company’s products or services on its space, and earns commission from it. This practice is known as Affiliate Marketing.

    Alt Text

    It is an HTML tag, where description of an image (or any other multimedia) can be inserted. For instance, when a visitor chooses ‘don’t display images’ for a website, the alt-text of an image is shown in place of the image.

    Anchor Text

    It is a clickable text on Hyperlink,The anchor text, link label, link text, or link title is the visible, clickable text in a hyperlink. The words contained in the anchor text can determine the ranking that the page will receive by search engines.


    It is also known as an inbound link. Suppose website A contains a hyperlink that directs to website B. For website B, that hyperlink is a backlink.


    cPanel & WHM is an online Linux-based web hosting control panel that provides a graphical interface (GUI) and automation tools designed to simplify the process of hosting a web site to the website owner or the \"end user\". cPanel & WHM utilizes a three-tier structure that provides capabilities for administrators, resellers, and end-user website owners to control the various aspects of website and server administration through a standard web browser


    PostgreSQL, also known as Postgres, is a free and open-source relational database management system (RDBMS) emphasizing extensibility and technical standards compliance. It is designed to handle a range of workloads, from single machines to data warehouses or Web services with many concurrent users. It is the default database for macOS Server,and is also available for Linux, FreeBSD, OpenBSD, and Windows.


    The NetScaler line of products are part of Citrix Systems\' networking business It includes NetScaler ADCs, NetScaler Unified Gateway, NetScaler AppFirewall, NetScaler SD-WAN, and NetScaler Management & Analytics System The products can work in conjunction with other Citrix offerings, including its Xen line of products


    Metadata is \"data information that provides information about other data\". Many distinct types of metadata exist, among these descriptive metadata, structural metadata, administrative metadata ,reference metadata and statistical metadata.

    Cache Control

    Cache-control is an HTTP header used to specify browser caching policies in both client requests and server responses. Policies include how a resource is cached, where it’s cached and its maximum age before expiring

    HTTP Compression

    HTTP compression is a capability that can be built into web servers and web clients to improve transfer speed and bandwidth utilization.

    Resource Hints

    This specification defines the dns-prefetch, preconnect, prefetch, and prerender relationships of the HTML Link Element. These primitives enable the developer, and the server generating or delivering the resources, to assist the user agent in the decision process of which origins it should connect to, and which resources it should fetch and preprocess to improve page performance.

    Load Impact

    LoadImpact is a leading online load and performance testing service that lets you test your website, web-app, mobile app or API locally or over the Internet.

    PHP accelerators

    A PHP accelerator is a PHP extension designed to improve the performance of software applications written in the PHP programming language. The way these PHP accelerators work is by caching the compiled bytecode of your human-readable PHP. Normally, your PHP code is compiled and then executed at runtime but these tools cache the compiled code, saving the expense of compiling it and thusly generally save you a bit of CPU at the cost of some increased memory usage.

    Cyber Flood

    CyberFlood is a powerful, easy-to-use testing platform that generates realistic application traffic and attacks to test the performance, scalability and security of today’s application-aware network infrastructures.

    Wpdb(WordPress Database)

    WordPress defines a class called wpdb, which contains a set of functions used to interact with a database. Its primary purpose is to provide an interface with the WordPress database, but can be used to communicate with any other appropriate database.


    JavaScript, often abbreviated as JS, is a high-level, interpreted scripting language that conforms to the ECMAScript specification. JavaScript has curly-bracket syntax, dynamic typing, prototype-based object-orientation, and first-class functions


    FiOS uses fiber optic cable made from hundreds of hair-like strands of glass to send pulses of light to carry data directly into a home computer. As the laser-generated pulses of light reach the subscriber\'s home, a converter changes them into electrical impulses that computers use.


    The alpha channel is an 8-bit channel, which means it has 256 levels of gray from 0 (black) to 255 (white). White acts as the visible area; black acts as the transparent area (you see the background behind the image when displayed).

    Media Attribute

    The media attribute specifies what media/device the linked document is optimized for. This attribute is used to specify that the target URL is designed for special devices (like iPhone) , speech or print media. This attribute can accept several values.

    Pixel Density

    The pixel density descriptors, also referred to as display or screen density descriptors, are an extremely helpful way of displaying high resolution images on high resolution displays. These descriptors are defined using 1x, 2x, and 3x. They allow an image to be displayed that is either two or three times larger than the original while retaining the same dimensions as the original image.


    The load time of your website also influences how easily users can find your website. Website speed is one of the factors that Google takes into consideration when ranking sites. A low performing website has a poor user experience and as a result gains less promotion in search results.


    Website usability like website page speed, load time, and website responsiveness to user requests directly impacts customer loyalty. The better your website performs, the more satisfied a user will be.


    Is also a great tool for website speed testing with a number of useful features. It tracks your website’s performance history, makes data-driven recommendations on how to improve the website speed, and generates easy to understand reports. Pingdom also provides the apps for website speed testing for Android and iOS.


    CF is a popular Content Delivery Network, which also offers Internet Security services. Plans start from free, but additional features are available for extra costs. CloudFlare is a fixed-cost CDN, meaning they charge by features instead of usage. CloudFlare allows you to route your sites traffic through their network before coming back to your origin host.


    lighttpd (nicknamed \"lighty\") is an open-source web server optimized for speed-critical environments while remaining standards-compliant, secure and flexible.


    HyperDB is a very advanced database class that replaces a few of the WordPress built-in database functions. The main differences are HyperDB can be connected to an arbitrary number of database servers, HyperDB inspects each query to determine the appropriate database.

    Content Optimization

    Content Optimization is a process in which a webpage and its content are optimized to become more attractive, useful and actionable to users. The processes typically include fixes and improvements on technical performance (ex: page speed) and content copy for it to perform and rank better on the search engines.

    Performance Counter

    Counters are used to provide information as to how well the operating system or an application, service, or driver is performing. ... The operating system, network, and devices provide counter data that an application can consume to provide users with a graphical view of how well the system is performing.

    Argo Smart Router

    It uses latency and packet loss data collected from each request that traverses our network to pick optimal paths across the Internet. Using this latency data, we\'re able to determine which of our transit providers are performing best between any two points on the planet

    Server Push

    It is where the server pushes a resource directly to the client without the client asking for the resource. The server is making an assumption here that pushing the resource is desirable. Pushing a cacheable resource can be risky, as the browser might already have the resource and the push can be redundant.

    Varnish Cache

    Varnish is a program that speeds up a website while reducing the load on the web server. You can accelerate the site performance using various other modules, such as Varnish purge and Advanced Varnish Cache.

    TLS (Transportation Layer Security)

    Transport Layer Security, and its now-deprecated predecessor, Secure Sockets Layer, are cryptographic protocols designed to provide communications security over a computer network. Several versions of the protocols find widespread use in applications such as web browsing, email, instant messaging, and voice over IP.

    FCP (First Contentful Paint)

    FCP measures the actual time that is taken by a user of the website to see a visual response from the page he is trying to open. It the page loads fast then it will help in keeping the visitor engaged. If not the visitor shall lose interest and shall leave the page. Load time will be very fast i.e. less than 0.4 seconds.

    DCL (Dom Content Loaded)

    DCL measures the time when the HTML document has been completely loaded and read. This exactly doesn’t mean that the web page has loaded, it just means that the main HTML of the page has been loaded completely. The page has to then finish loading the images and stylesheets to make the page fully accessible to the user.

    Field Data

    A data field is a place where you can store data. Commonly used to refer to a column in a database or a field in a data entry form or web form. The field may contain data to be entered as well as data to be displayed.

    Time to Interactive (TTI)

    Time to Interactive (TTI) is one of six metrics tracked in the performance section of the Lighthouse report. Each of these metrics captures some aspect of page load speed. The Lighthouse reports displays the Time to Interactive period in seconds


    When you choose to aggregate CSS and JavaScript files, “Bandwidth Optimization” groups both in bundles in order to reduce the number of HTTP requests, which is necessary for the page to load. Instead of loading a couple dozens of files, the page will load with just a handful of aggregates.


    Redis is a cache technique that is optimized for high-performance storage and retrieval. It works with an in-memory dataset. Have a look at Redis module for a detailed explanation.

    Anxiety Elements

    From an optimization perspective, anxiety elements are parts of a web page that create anxiety for your visitors and reduce their inclination to convert on your page


    A cookie is a piece of data that a website stores in a visitor’s browser to track that visitor’s browsing history on your website. It\'s also a crucial component of the technology behind personalization.


    Eyetracking is a form of website testing that follows eye movements of experiments\' participants to gauge how they interact with web pages. This provides insight into the most important real estate on your pages.


    A form is the place your page visitors will supply information in exchange for your offer. It’s also how those visitors can convert into precious sales leads. As a best practice, only ask for information you need from your leads in order to effectively follow up with and/or qualify them.


    Friction is any element of your website that is confusing, distracting, or causes stress for visitors, causing them to leave your page. Examples of friction-causing elements include dissonant colors, too much text, distracting website navigation menus, or landing page forms with too many fields.


    An incentive is an element you add to your page that stimulates the visitor to convert. In optimization circles, online incentives are used to overcome the friction on the page. Examples include a visual that reinforces the value of your offer, or a free trial or cost calculator you offer in exchange for downloading a report or taking a survey.

    Landing Page Optimization

    Landing Page Optimization is the process by which companies work to optimize their landing pages using design techniques, key optimization principles, and testing. This is also sometimes called Website Optimization or Conversion Rate Optimization.

    Latent Conversion

    A latent conversion is a type of conversion that takes place after your visitor’s initial visit. For example, someone may look for a price matrix, leave your page to think about it, come back to your website two days later, and then make a purchase.

    Longtail Keyword

    A long tail keyword is a very targeted search phrase that contains three or more words. It often contains a head term, which is a more generic search term, plus one or two additional words that refine the search term.


    A microsite is a cross between a landing page and a “regular” website. Microsites are used when marketers want to create a different online experience for their audience separate from their main website. These sites often have their own domain names and distinct visual branding.


    Personalization is a means of targeting your audience, so that each web page or email message appears to have been created specifically for a single person. Examples of personalization include adding a name to an email subject line, showing products based on the visitor’s past purchase history, or surfacing dynamic images based on location or industry.

    Value Exchange

    The value exchange is the process by which your website promotes something of value in order to get information from your visitors. For example exchanging a thought leadership ebook for personal contact information would be an online value exchange.

    Server Load

    The amount of traffic on your server and how it’s configured to handle the load will have a huge impact as well. For example, if you don’t use a caching solution, performance will slow to a halt as additional page requests come in and stack up, often crashing your web or database server.


    W3TC manages the headers (entity tag, cache-control, expires) which control the caching of files in web browsers, reducing server load and improving the user’s perceived performance.


    It improves the user experience of your site by improving your server performance, caching every aspect of your site, reducing the download times and providing transparent content delivery network (CDN) integration.

    Concurrent Users

    The website should not be designed for a single user or single user at a time usages it should be able to let many users concurrently access and fetch data from the website Understanding this metric – and how it is connected with average response time , will help the development of a high-performance web application.

    Request Per Second

    Requests per second measures how many actions are being sent to the target server every second. Any resources on the page is considered a request. Requests per second will vary greatly on the type of resource requested and how that request is processed.

    Error Rate

    The error rate is a calculation that measures the percentage of problem requests (errors) compared to all requests. Error rates should be measured with different loads. An acceptable error rate may differ from company to company, but this metric helps businesses and IT managers understand pinpoint when the application will fail.

    Peak Response Time

    The peak response time metric will help identify areas where performance could be improved. For example, the average response time might be one second, but within that average, there could be an element taking 10 seconds to load (the peak response time) while other elements are transferring in less than a second. The peak response time metric shows the slow elements within the application that should be investigated and changed.


    Parallel computing is a type of computation in which many calculations or the execution of processes are carried out simultaneously. Large problems can often be divided into smaller ones, which can then be solved at the same time. There are several different forms of parallel computing: bit-level, instruction-level, data, and task parallelism. Parallelism has long been employed in high-performance computing, but it\'s gaining broader interest due to the physical constraints preventing frequency scaling.


    An Internet backbone refers to one of the principal data routes between large, strategically interconnected networks and core routers on the Internet. A network backbone is a part of computer network infrastructure that interconnects various pieces of network, providing a path for the exchange of information between different LANs or subnetworks.

    Critical Path

    Critical Path analysis is the mathematical network analysis technique of planning complex working procedures with reference to the critical path of each alternative system.

    E2E (End 2 End ) Page Load Performance

    End to End page load performance measures the performance of a page from the initial request for the base HTML document to the loading and render of the final asset, including any assets that are delivered late or lazy loaded such as 3rd party marketing tags. As such it’s a useful number to know, but not indicative of real user experience.

    Forward Proxy

    A forward proxy is used to forward outgoing requests from a private network or intranet to the Internet, usually through a firewall.

    JavaScript Blocking

    JavaScript blocking stops JavaScript from running on the web page which can hurt performance, stop the rendering of the webpage completely, or cause the page to become unresponsive.

    Code Profiling

    Typically they’re used by developers, without changing their code, to help identify performance problems. It can answer questions like how many times each method in your code is called and how long does each of those methods take. It tracks things like memory allocations and garbage collection. Some profilers also track key methods in your code so you can understand how often SQL statements are called and web service calls. Some profilers can track web requests and train those transactions to understand the performance of transactions within your code.

    Complex Test Layout

    Complex text layout or complex text rendering is the typesetting of writing systems in which the shape or positioning of a grapheme depends on its relation to other graphemes. The term is used in the field of software internationalization, where each grapheme is a character.

    SOAP Monitoring

    SOAP monitoring allows you to test the ability to connect and push sample data into a web service to ensure functionality from multiple locations around the world.Once you add a SOAP monitor for your website, Monitis will start sending out SOAP requests to your web service at your preset regular intervals of time to check if your web service is accessible.

    DOM (Document Object Model)

    The Document Object Model is a cross- platform and language- independent interface that treats an XML or HTML document as a tree structure wherein each node is an object representing a part of the document.The DOM content loaded, this is when the HTML is completely loaded and parsed. So some really good ones to keep an eye on and just to be aware of in general.

    Consistently Interactive

    Depending on what is loaded, and how it’s loaded, that this delayed JavaScript could cause hiccups in the interactivity of the page. Thus, keeping an eye on the Time to Consistently Interactive can give us an idea of if there are issues after the initial load that we may need to address.


    It’s an online visibility and marketing analytics software, It tracks the keyword strategy used by your competition, runs as SEO audit of your blog , looks for backlinking opportunities and lots more.


    Kernel32.dll is the 32-bit dynamic link library found in the Windows Operating system kernel. It handles memory management, input/output operations, and interrupts. When Windows boots up, kernel32.dll is loaded into a protected memory space so other applications do not take that space over. On occasion, though, users may encounter the \"invalid page fault\" error. This error occurs when a program or application tries to access kernel32.dll\'s protected memory space. Sometimes the error is caused by one particular program or application, and other times it is provoked by multiple files and applications.

    Unified Extensible Firmware Interface (UEFI)

    Unified Extensible Firmware Interface (UEFI) is a specification for a software program that connects a computer\'s firmware to its operating system (OS). UEFI replaces BIOS, enhances the Extensible Firmware Interface (EFI) and provides an operational environment for OS and boot-time applications and services. UEFI can support remote diagnostics and repair of computers, even with no operating system installed.


    Bricking refers to a consumer electronic device that has been damaged beyond repair, making it utterly unusable, often because of damaged firmware. The use of the term stems from the brick-like shape of many consumer gadgets, and the fact that once they are rendered inoperative, they are virtually useless except as a paperweight or a doorstop. Strictly speaking, a device is bricked when it completely loses its functionality. However, the term is being used with more flexibility these days, and in some cases, bricked electronics are still recoverable with some hardware replacement or additional software.

    Host-based modem

    A host-based modem is a modem that uses a computer\'s CPU for certain processing duties, facilitating lower-priced modems and modem circuits. Because host-based modems require less processing power of their own, they should be less expensive than conventional modems. In the PC world, host-based modems are sometimes called Winmodems.

    Virtual memory

    Virtual memory is a memory management capability of an operating system (OS) that uses hardware and software to allow a computer to compensate for physical memory shortages by temporarily transferring data from random access memory (RAM) to disk storage. Virtual address space is increased using active memory in RAM and inactive memory in hard disk drives (HDDs) to form contiguous addresses that hold both the application and its data.

    Connected Limited Device Configuration (CLDC)

    The Connected Limited Device Configuration (CLDC) is a specification of a framework for Java ME applications describing the basic set of libraries and virtual-machine features that must be present in an implementation. The CLDC is combined with one or more profiles to give developers a platform for building applications on embedded devices with very limited resources such as pagers and mobile phones. CLDC is one of two configurations under the Java Platform Micro Edition (Java ME). Compared to the devices supported by another configuration (called Connected Device Configuration), CLDC-supported devices have more constrained hardware resources, including RAM, screen size and resolution, and CPU.


    JXTA is an open-source Java-based application development protocol set that facilitates peer-to-peer (P2P) communication for connected network devices, such as mobile phones, computers and servers. JXTA is derived from the word juxtapose.

    Peer-to-peer architecture (P2P architecture)

    Peer-to-peer architecture (P2P architecture) is a commonly used computer networking architecture in which each workstation, or node, has the same capabilities and responsibilities. It is often compared and contrasted to the classic client/server architecture, in which some computers are dedicated to serving others.

    IETF (Internet Engineering Task Force)

    The IETF (Internet Engineering Task Force) is the body that defines standard Internet operating protocols such as TCP/IP. The IETF is supervised by the Internet Society Internet Architecture Board (IAB). IETF members are drawn from the Internet Society\'s individual and organization membership. IETF is an open organization that does not have any formal membership. All employees and management personnel are volunteers. Annual, bi-annual and quarterly meetings are arranged to discuss previous and future developments regarding different projects and Internet standards.

    SDP (Session Description Protocol)

    SDP (Session Description Protocol) is a set of rules that define how multimedia sessions can be set up to allow all end points to effectively participate in the session. In this context, a session consists of a set of communications end points along with a series of interactions among them. An SDP file contains information about the format, timing and authorship of the transmission, name and purpose of the session, any media, protocols or codec formats, the version number, contact information and broadcast times.

    UDP (User Datagram Protocol)

    UDP (User Datagram Protocol) is a communication protocol used across the Internet for especially time-sensitive transmissions such as video playback or DNS lookups. It speeds up communications by not requiring what’s known as a “handshake”, allowing data to be transferred before the receiving party agrees to the communication. This allows the protocol to operate very quickly, and also creates an opening for exploitation.

    OLTP (online transaction processing)

    OLTP (online transaction processing) is a class of software programs capable of supporting transaction-oriented applications on the Internet. In computing, a transaction is a sequence of discrete information exchanges that are treated as a unit. Many everyday acts involve OLTP, including online banking, online shopping.OLTP’s primary system features are immediate client feedback and high individual transaction volume.

    Web Standards Project (WaSP)

    The Web Standards Project (WaSP) was a group of professional web developers dedicated to disseminating and encouraging the use of the web standards recommended by the World Wide Web Consortium, along with other groups and standards bodies.

    Connect Time

    Connect time is the time taken to establish a TCP connection between the server and the client. TCP/IP model guarantees delivery of data by its nature by using the TCP Handshake. If TCP Handshake is successful, then the client can send further requests. That data send/receive task is not on the HTTP layer. If there’s no TCP connection made between the server and the client, the client can’t talk to the server. This can happen if the server is not live or busy responding to other requests.

    Information scent

    Information scent refers to the strength of relevant messaging throughout the customer journey as well as visual and textual cues that provide website visitors with hints on what information a site contains. A strong information scent is important to convince users they will find what they’re looking for at the end of their journey, as they follow links that bring them closer to their end goal. There should be nothing alarming, disjointed or confusing for a user as they move throughout a conversion funnel.

    Life Time Value (LTV)

    Life Time Value or LTV is an estimate of the average revenue that a customer will generate throughout their lifespan as a customer. This ‘worth’ of a customer can help determine many economic decisions for a company including marketing budget, resources, profitability and forecasting. It is a key metric in subscription based business models, along with MRR (Monthly Recurring Revenue).

    Visitor segmentation

    Visitor segmentation is the process of dividing your visitors to your website, viewers of digital ads, marketing email recipients, etc. based on a specific criteria, such as demographics or user behavior. Since segmentation organizes individuals into consistent groups, it is possible to present that segment with a customized experience—rather than presenting a single, broad experience for every individual—that the particular audience will respond to more positively.

    Server-side testing

    Server-side A/B testing is a form of experimentation where the variations of a test are rendered directly on the web server, before it is delivered to the client. This is distinguished from client-side testing, where the A/B test is rendered on the client-side through JavaScript after the page is delivered to the user’s browser.

    User journey map

    A user journey map (also known as a customer journey map) is a diagram that visually illustrates the user flow through your site, starting with initial contact or discovery, and continuing through the process of engagement into long-term loyalty and advocacy. It identifies key interactions and touchpoints with your website or mobile app and describes in detail the customer’s goals, motivations, and feelings at each step.

    User flow

    User flow is the path taken by a prototypical user on a website or app to complete a task. The user flow takes them from their entry point through a set of steps towards a successful outcome and final action, such as purchasing a product.

    Usability testing

    Usability testing is a method of evaluating a website or app’s readiness for release by testing it with real users who are part of the target audience. This testing mainly focuses on the user\'s ease to use the application, flexibility in handling controls and the ability of the system to meet its objectives. It is also called User Experience(UX) Testing.

    Web analytics

    Web analytics is the measurement and analysis of data to inform an understanding of user behavior across web pages. Analytics platforms measure activity and behavior on a website, for example: how many users visit, how long they stay, how many pages they visit, which pages they visit, and whether they arrive by following a link or not.

    Exploratory stress testing

    Exploratory stress testing is an approach to subjecting a system, application, or component to a set of unusual parameters or conditions that are unlikely to occur in the real world but are nevertheless possible. In general, exploratory testing can be viewed as an interactive process of simultaneous learning, test design, and test execution. Most often, exploratory stress tests are designed by modifying existing tests and/or working with application/system administrators to create unlikely but possible conditions in the system. This type of stress testing is seldom conducted in isolation because it is typically conducted to determine if more systematic stress testing is called for related to a particular failure mode.

    Continuous Delivery

    Continuous Delivery is the software development process of getting code changes into production quickly, safely and with higher quality usually using tools to automate the deploys. It aims at building, testing, and releasing software with greater speed and frequency. The approach helps reduce the cost, time, and risk of delivering changes by allowing for more incremental updates to applications in production.

    OCSP stapling

    OCSP stapling is a method for quickly and safely determining whether or not an SSL certificate is valid. It allows a web server to provide information on the validity of its own certificates rather than having to request the information from the certificate’s vendor.


    Greynet refers to applications such as messenger, chat, file sharing and media streaming that users who belong to a corporate network download without the permission of their network administrators. The problem with graynet applications is that they consume corporate time and computer resources. These applications also provide an open door through which end user systems may be compromised by malware or viruses.

    Thin client

    A thin client is a networked computer with few locally stored programs and a heavy dependence on network resources. It is a low-cost endpoint computing device that relies heavily on a server for its computational role. The term thin client is also used to describe software applications that use the client-server model in which the server performs all the processing.

    Data definition language (DDL)

    A data definition language (DDL) is a computer language used to create and modify the structure of database objects in a database. DDL statements create, modify, and remove database objects such as tables, indexes, and users. Common DDL statements are CREATE, ALTER, and DROP.

    Microsoft Interface Definition Language (MIDL)

    Microsoft Interface Definition Language (MIDL) defines interfaces between client and server programs. Microsoft includes the MIDL compiler with the Platform SDK to enable developers to create the interface definition language (IDL) files and application configuration files (ACF) required for remote procedure call interfaces and COM/DCOM interfaces.


    Sharding is a type of database partitioning that separates very large databases into smaller, faster, more easily managed parts called data shards. The word shard means a small part of a whole.

    DNS prefetching

    DNS prefetching allows the browser to perform the DNS lookups for links on a page in the background while the user browses the current page. This minimizes latency as when the user clicks on a link with DNS prefetch enabled, they do not have to wait for the DNS lookup to take place as it already has.


    Prerendering is similar to prefetching in that it gathers the resources needed to display a page that the user may navigate to next. Although the main difference is that instead of just downloading the required resources, prerendering actually renders the entire page in the background. The page is hidden, although if the user navigates to the page, the hidden page will replace the current tab and will display the page the user requested.

    Key performance indicators (KPI)

    Key performance indicators (KPI) are measurements used to identify and quantify business performance. KPIs are selected through a management framework. To identify and establish the critical KPIs, an enterprise process must be created to meet the following requirements: Contain clear objectives Be measurable, quantitatively and qualitatively Identify and resolve organizational variances

    Remote monitoring and management (RMM)

    Remote monitoring and management (RMM) is a collection of information technology tools that are loaded to client workstations and servers. These tools gather information regarding the applications and hardware operating in the client’s location as well as supply activity reports to the IT service provider, allowing them to resolve any issues. RMM usually provides a set of IT management tools like trouble ticket tracking, remote desktop monitoring, support and user information through a complete interface.

    Routing and remote access service (RRAS)

    Routing and remote access service (RRAS) is a suite of network services in the Windows Server family that enables a server to perform the services of a conventional router. RRAS includes an application programming interface (API) that facilitates the development of applications and processes for administering a range of network services.

    Remote Authentication Dial-In User Service (RADIUS)

    Remote Authentication Dial-In User Service (RADIUS) is a network protocol that provides security to networks against unauthorized access. RADIUS secures a network by enabling centralized authentication of dial-in users and authorizing their access to use a network service. It manages remote user authentication, authorization and accounting (AAA).

    Professional services automation (PSA)

    Professional services automation (PSA) is a process through which routine tasks and procedures in the professional services industry are automated through a software application or an IT system. Professional services automation involves the creation, termination and management of a set of processes. It is often used by project managers, consultants and other service-oriented professionals and businesses.

    Authentication, authorization and accounting (AAA)

    Authentication, authorization and accounting (AAA) is a system for tracking user activities on an IP-based network and controlling their access to network resources. AAA is often is implemented as a dedicated server. This term is also referred to as the AAA Protocol.

    Server-side scripting

    Server-side scripting is a method of designing websites so that the process or user request is run on the originating server. Server-side scripts provide an interface to the user and are used to limit access to proprietary data and help keep control of the script source code.

    Progressive Enhancement (PE)

    Progressive Enhancement is a powerful methodology that allows Web developers to concentrate on building the best possible websites while balancing the issues inherent in those websites being accessed by multiple unknown user-agents. Progressive Enhancement (PE) is the principle of starting with a rock-solid foundation and then adding enhancements to it if you know certain visiting user-agents can handle the improved experience.

    Graceful degradation

    Graceful degradation is the ability of a computer, machine, electronic system or network to maintain limited functionality even when a large portion of it has been destroyed or rendered inoperative. The purpose of graceful degradation is to prevent catastrophic failure. Ideally, even the simultaneous loss of multiple components does not cause downtime in a system with this feature. In graceful degradation, the operating efficiency or speed declines gradually as an increasing number of components fail.

    Unobtrusive JavaScript

    is a general approach to the use of JavaScript in web pages. Though the term is not formally defined, its basic principles are generally understood to include: Separation of functionality (the \"behavior layer\") from a Web page\'s structure/content and presentation Best practices to avoid the problems of traditional JavaScript programming (such as browser inconsistencies and lack of scalability) Progressive enhancement to support user agents that may not support advanced JavaScript functionality

    Software brittleness

    In computer programming and software engineering, software brittleness is the increased difficulty in fixing older software that may appear reliable, but fails badly when presented with unusual data or altered in a seemingly minor way.

    Failure transparency

    In a distributed system, failure transparency refers to the extent to which errors and subsequent recoveries of hosts and services within the system are invisible to users and applications. For example, if a server fails, but users are automatically redirected to another server and never notice the failure, the system is said to exhibit high failure transparency.


    In systems design, a fail-fast system is one which immediately report at its interface any condition that is likely to indicate a failure. Fail-fast systems are usually designed to stop normal operation rather than attempt to continue a possibly flawed process. Such designs often check the system\'s state at several points in an operation, so any failures can be detected early.

    Control reconfiguration

    Control reconfiguration is used when severe faults, such as actuator or sensor outages, cause a break-up of the control loop, which must be restructured to prevent failure at the system level. In addition to loop restructuring, the controller parameters must be adjusted to accommodate changed plant dynamics. Control reconfiguration is a building block toward increasing the dependability of systems under feedback control.

    Failure semantics

    In distributed computing, failure semantics is used to describe and classify errors that distributed systems can experience.


    In computer networking resilience is the ability to provide and maintain an acceptable level of service in the face of faults and challenges to normal operation. Threats and challenges for services can range from simple misconfiguration over large scale natural disasters to targeted attacks. As such, network resilience touches a very wide range of topics. In order to increase the resilience of a given communication network, the probable challenges and risks have to be identified and appropriate resilience metrics have to be defined for the service to be protected.

    Multipath routing

    Multipath routing is the routing technique of using multiple alternative paths through a network, which can yield a variety of benefits such as fault tolerance, increased bandwidth, or improved security. The multiple paths computed might be overlapped, edge-disjointed or node-disjointed with each other. Extensive research has been done on multipath routing techniques, but multipath routing is not yet widely deployed in practice.

    Data redundancy

    Data redundancy is a condition created within a database or data storage technology in which the same piece of data is held in two separate places. This can mean two different fields within a single database, or two different spots in multiple software environments or platforms. Whenever data is repeated, this basically constitutes data redundancy. This can occur by accident, but is also done deliberately for backup and recovery purposes.

    Data scrubbing

    Data scrubbing refers to the procedure of modifying or removing incomplete, incorrect, inaccurately formatted, or repeated data in a database. The key objective of data scrubbing is to make the data more accurate and consistent. Data scrubbing is a vital strategy for ensuring that databases remain accurate. It is especially important in data-intensive industries, including telecommunications, insurance, banking and retailing. Data scrubbing systematically evaluates data for flaws or mistakes with the help of look-up tables, rules and algorithms. Data scrubbing is also referred to as data cleansing.

    Crash-only software

    Crash-only software refers to computer programs that handle failures by simply restarting, without attempting any sophisticated recovery. Correctly written components of crash-only software can micro reboot to a known-good state without the help of a user. Since failure-handling and normal startup use the same methods, this can increase the chance that bugs in failure-handling code will be noticed, except when there are leftover artifacts, such as data corruption from a severe failure, that don\'t occur during normal startup.

    Comma separated values (CSV)

    A comma separated values (CSV) file contains different values separated by a delimiter, which acts as a database table or an intermediate form of a database table. In other words, a CSV file is a set of database rows and columns stored in a text file such that the rows are separated by a new line while the columns are separated by a semicolon or a comma. A CSV file is primarily used to transport data between two databases of different formats through a computer program.

    Z Object Publishing Environment (Zope)

    Z Object Publishing Environment (Zope) is an open source Web Server built using Python. It encompasses a transactional database that stores content, HTML templates, scripts and features a search engine along with an RDBMS. Zope simplifies the creation of dynamic Web apps and offers application-based support such as membership, news and search. Zope is built completely using open standards such as XML-RPC, DOM and WebDAV.

    Abstract IL

    Abstract IL (Intermediate Language) is a software development Kit (SDK) consisting of libraries, documentation and other development tools that can be used to manipulate the contents of .NET framework and binary files at a high level.


    It is the level of detail at which data are stored in a database. When the same data are represented in multiple databases, the granularity may differ.


    Effective vectorization comes from a combination of efficient data movement and recognition of vectorization opportunities in the program itself. Many things get in the way of vectorization: poor data layout, C/C++ language limitations, required compiler conservatism, and poor program structure.


    Parallelization is the act of designing a computer program or system to process data in parallel. Normally, computer programs compute data serially: they solve one problem, and then the next, then the next. If a computer program or system is parallelized, it breaks a problem down into smaller pieces that can each independently be solved at the same time by discrete computing resources. When optimized for this type of computation, parallelized programs can arrive at a solution much faster than programs executing processes in serial.


    It is designed to manipulate numbers or perform some other specialized function more quickly than the basic microprocessor circuits could perform the same task. A coprocessor offloads specialized processing operations, thereby reducing the burden on the basic microprocessor circuitry and allowing it to work at optimum speed.

    Hardware Threads

    Hardware threads are a feature of some processors that allow better utilisation of the processor under some circumstances. They may be exposed to/by the operating system as appearing to be additional cores (\"hyperthreading\")

    Memory traffic

    Excessive allocations and garbage collections may imply significant memory management overhead. For example, you have an array of objects which should be updated over time. You can update each object in two ways: by creating a new instance with required properties or by updating properties of the existing instance. From a functional perspective, both options are the same. But from the point of memory management workload, creating a new instance all the time is much less effective.

    Memory Bandwidth

    Memory bandwidth is the rate at which data can be read from or stored into a semiconductor memory by a processor. Memory bandwidth is usually expressed in units of bytes/second, though this can vary for systems with natural data sizes that are not a multiple of the commonly used 8-bit bytes.

    Cache Hit Rates

    The percentage of accesses that result in cache hits is known as the hit rate or hit ratio of the cache. The alternative situation, when the cache is checked and found not to contain any entry with the desired tag, is known as a cache miss. This requires a more expensive access of data from the backing store.

    L1 Cache

    L1 is the levels of cache memory in a computer. If the computer processor can find the data it needs for its next operation in cache memory, it will save time compared to having to get it from random access memory. L1 is \"level-1\" cache memory, usually built onto the microprocessor chip itself. For example, the Intel MMX microprocessor comes with 32 thousand bytes of L1.

    Memory Hierarchy

    The memory hierarchy separates computer storage into a hierarchy based on response time. Since response time, complexity, and capacity are related, the levels may also be distinguished by their performance and controlling technologies.[1] Memory hierarchy affects performance in computer architectural design, algorithm predictions, and lower level programming constructs involving locality of reference.

    Network Optimization

    Network optimization is technology used for improving network performance for a given environment. It is considered an important component of effective information systems management. Network optimization plays an important role as information technology is growing at exponential rates with business users producing large volumes of data and thus consuming larger network bandwidths.

    Iteration Loop

    In computer science, a for-loop (or simply for loop) is a control flow statement for specifying iteration, which allows code to be executed repeatedly.

    Static web page

    A static Web page is a page that is built using HTML code and features the same presentation and content, regardless of user identity or other factors. Static Web pages are easier to code and assemble than dynamic Web pages, which may feature customizable content according to a user\'s identity or other factors. Static Web pages are also known as static websites.

    Static URL

    A static URL is a URL that does not change depending on input from a remote database or server, but stays the same with each page load. Static URLs are the norm for pages that do not contain interactive elements based on the results of a web administrator’s remote data.

    Aspect-oriented programming (AOP)

    Aspect-oriented programming (AOP) is a programming paradigm that isolates the supporting functions from the main program’s business logic.


    In software engineering, modularity refers to the extent to which a software/Web application may be divided into smaller modules. Software modularity indicates that the number of application modules are capable of serving a specified business domain. Modularity is successful because developers use prewritten code, which saves resources. Overall, modularity provides greater software development manageability.

    Modular programming

    Modular programming is the process of subdividing a computer program into separate sub-programs. A module is a separate software component. It can often be used in a variety of applications and functions with other components of the system. Similar functions are grouped in the same unit of programming code and separate functions are developed as separate units of code so that the code can be reused by other applications.


    Single-sourcing is the use of a single document to produce other forms of documents, such as manuals and online help. It allows one document to be used in different kinds of formats, thereby increasing the usability of the documentation. Single-sourcing also eliminates duplicate work and facilitates the reuse of existing information, which saves time and money. Single-sourcing is also known as single source publishing.


    A module is a software component or part of a program that contains one or more routines. One or more independently developed modules make up a program. An enterprise-level software application may contain several different modules, and each module serves unique and separate business operations. Modules make a programmer\'s job easier by allowing the programmer to focus on only one area of the functionality of the software application. Modules are typically incorporated into the program (software) through interfaces.

    Source code

    Source code is a set of instructions and statements written by a programmer using a computer programming language. This code is later translated into machine language by a compiler. The translated code is referred to as object code.


    On the Internet, a masthead is a graphic image or text title at the top of a Web page that identifies the Web site and, sometimes, the particular section of the site. In addition to the name of the Web site, a masthead could include other elements such as images, text, or navigational links.

    Dynamic URL

    A dynamic URL is the address - or Uniform Resource Locator (URL) - of a Web page with content that depends on variable parameters that are provided to the server that delivers it. The parameters may be already present in the URL itself or they may be the result of user input. A dynamic URL can often be recognized by the presence of certain characters or character strings that appear in the URL (visible in the address bar of your browser). The following are representative: & $ + = ? % cgi

    Enterprise Feedback Management (EFM)

    Enterprise Feedback Management (EFM) is an enterprise-wide and centrally panel managed system of processes and survey software that facilitates data collection, authoring, statistical analysis and reporting. EFM involves a workflow process ensuring quality surveys consistently administered with assured privacy through IT security policies. EFM’s purpose is to facilitate communication and dialog between the enterprise and employees, customers, and business partners to address key issues and concerns. Potentially, this can make possible real time customer interventions.

    Scripting engine

    A scripting engine is commonly defined as a vehicle for implementing scripts in scripting languages. These differ from other programming languages commonly called \"system programming languages.\" Although the line between scripting languages and other languages may be somewhat difficult to demarcate, scripting languages are generally built on platforms that allow code to be written with a little more automation than the traditional method of writing executable code by hand.

    Visual Basic Script (VBScript)

    Visual Basic Script (VBScript) is a component-based scripting language developed by Microsoft. It is a light version of Visual Basic with a fast interpreter for use on Microsoft platforms. VBScripts use the Component Object Model (COM) to access the features of the environment where they are running. VBScripts are executed in the host environment.

    Logic error

    A logic error is an error in a program’s source code that gives way to unanticipated and erroneous behavior. A logic error is classified as a type of runtime error that can result in a program producing an incorrect output. It can also cause the program to crash when running. Logic errors are not always easy to recognize immediately. This is due to the fact that such errors, unlike that of syntax errors, are valid when considered in the language, but do not produce the intended behavior. These can occur in both interpreted and compiled languages. A logic error is also known as a logical error.

    Shared Source

    Shared Source is Microsoft’s mechanism for legal distribution of software source code. This venture was initially launched in May 2001 and includes numerous licenses and technologies. Microsoft’s Shared Source permits both organizations and individuals to access a program\'s source code as a reference. This access provides developers with debug capabilities, which can be downloaded after satisfying certain eligibility criteria. The associated license may range from only code viewing for reference to permission for modification, which can be used for commercial and noncommercial purposes.

    Extensible Markup Language (XML)

    Extensible Markup Language (XML) is a universal format, maintained by the W3C, used for representation and transfer of structured data on the web or between different applications.

    Command line interface (CLI)

    Command line interface (CLI) is a text-based interface that is used to operate software and operating systems while allowing the user to respond to visual prompts by typing single commands into the interface and receiving a reply in the same way. CLI is quite different from the graphical user interface (GUI) that is presently being used in the latest operating systems.

    Command prompt

    The command prompt (cmd.exe) is a native Windows application meant to act as a command-line interpreter. It was created by Microsoft for the OS/2, Windows CE and Windows NT-based operating systems, which includes Windows 2000, XP and currently Windows 8 as well as various server versions of Windows. It is not a DOS program but a real executable application. As the name suggests, the command prompt is used to issue various commands to the system, like file management commands such as copy and delete. It also acts as a user interface.

    Syntax error

    A syntax error in computer science is an error in the syntax of a coding or programming language, entered by a programmer. Syntax errors are caught by a software program called a compiler, and the programmer must fix them before the program is compiled and then run.

    Programming logic

    Programming logic is a fundamental construct that\'s applied to computer science in a variety of comprehensive ways. Programming logic involves logical operations on hard data that works according to logical principles and quantifiable results.

    Runtime error

    Runtime error refers to an error that takes place while executing a program. As opposed to the compilation errors that occur during a program compilation, runtime errors occur only during the execution of the program. Runtime errors imply bugs in the program or issues that the developers had expected but were unable to correct. For example, insufficient memory can often trigger a runtime error. Runtime errors usually appear in a message box that includes a specific error code coupled with its corresponding description. It is quite common that the computer becomes noticeably slow prior to the appearance of a runtime error.

    Design pattern

    A design pattern is a repeatable solution to a software engineering problem. Unlike most program-specific solutions, design patterns are used in many programs. Design patterns are not considered finished product; rather, they are templates that can be applied to multiple situations and can be improved over time, making a very robust software engineering tool. Because development speed is increased when using a proven prototype, developers using design pattern templates can improve coding efficiency and final product readability.

    Command-line option

    Command-line options are commands used to pass parameters to a program. These entries, also called command-line switches, can pass along cues for changing various settings or executing commands in an interface.

    Object-oriented programming (OOP)

    Object-oriented programming (OOP) is a software programming model constructed around objects. This model compartmentalizes data into objects (data fields) and describes object contents and behavior through the declaration of classes (methods). Object-oriented programming allows for simplified programming. Its benefits include reusability, refactoring, extensibility, maintenance and efficiency.

    Markup language

    A markup language is a computer language that uses tags to define elements within a document. It is human-readable, meaning markup files contain standard words, rather than typical programming syntax. While several markup languages exist, the two most popular are HTML and XML.

    Run time

    Run time is a phase of a computer program in which the program is run or executed on a computer system. Run time is part of the program life cycle, and it describes the time between when the program begins running within the memory until it is terminated or closed by the user or the operating system. Run time is also known as execution time.


    ASP.NET is a unified web development model integrated with .NET framework, designed to provide services to create dynamic web applications and web services. It is built on the Common Language Runtime (CLR) of the .NET framework and includes those benefits like multi-language interoperability, type safety, garbage collection and inheritance.

    DETFF (Dual Edge-Triggered FlipFlop)

    It allows one to maintain a constant throughput while operating at only half the clock frequency . In DETFF, the optimal delay, power consumption, and energy are determined as the primary figures of merit.

    SETFF (Single Edge Triggered Flip Flop)

    A conventional single edge-triggered (SET) flip-flop typically latches data either on the rising of the falling edge of the clock cycle and offers better performance in terms of both power consumption and speed as compared to double edge triggered flip-flop

    Timing Parameters

    This can be defined as , when normally a field server sends a poll request to a server device and that device gives a response back to the Fieldserver. Three types of server 1. SETUP TIME 2. HOLD TIME 3. PROPAGATION TIME


    An interrupt signal generated by a program or device that has waited for a certain length of time for some input but has not received it. Many programs perform time-outs so that the program does not sit idle waiting for input that may never come.


    A dashboard is a reporting tool that consolidates, aggregates and arranges measurements, metrics (measurements compared to a goal) and sometimes scorecards on a single screen so information can be monitored at a glance


    A subroutine is a sequence of program instructions that performs a specific task, packaged as a unit. This unit can then be used in programs wherever that particular task should be performed.

    Channel Flow

    Channel Flow is defined as the objectives which is based on the customer requirements the marketing strategy, and the company strategy and objectives. The flow is defined as, Growth in sales by reaching new markets and/or increasing sales in existing markets. Maintenance or improvement of market share Achieve a pattern of distribution by a certain time, place, and form Reduce costs or increase profits by creating an efficient channel

    Balanced scorecard

    An integrated framework for describing strategy through the use of linked performance measures in four, balanced perspectives ‐ Financial, Customer, Internal Process, and Employee Learning and Growth. The Balanced Scorecard acts as a measurement system, strategic management system, and communication tool.

    Resident Threads

    An important specification in the compute capability is the maximum number of resident threads per multiprocessor.

    Running Threads

    Multithreading can allow an application to remain responsive to input. In a one-thread program, if the main execution thread blocks on a long-running task, the entire application can appear to freeze. By moving such long-running tasks to a worker thread that runs concurrently with the main execution thread, it is possible for the application to remain responsive to user input while executing tasks in the background.

    L2 Cache

    A memory bank built into the CPU chip, packaged within the same module or built on the motherboard. The L2 cache feeds the L1 cache, which feeds the processor. L2 memory is slower than L1 memory.

    Memory Access Pattern

    It is the pattern with which a system or program reads and writes memory on secondary storage. These patterns differ in the level of locality of reference and drastically affect cache performance and also have implications for the approach to parallelism and distribution of workload in shared memory systems

    Texture Memory

    Texture memory is a type of digital storage that makes texture data readily available to video rendering processors (also known as GPUs), typically 3D graphics hardware. It is most often (but not always) implemented as specialized RAM (TRAM) that is designed for rapid reading and writing, enabling the graphics hardware increased performance in rendering 3D imagery.

    Effective Bandwidth

    Effective bandwidth is the frequency interval where the start and end frequencies correspond to the half of the particle velocity at the design frequency (3dB bandwidth).the effective bandwidths can be found by an analytical expression. In many situations, however, the effective bandwidth has to be determined by estimation from traffic data.

    GMA (Global Memory Access)

    Whenever a thread on the GPU reads or write global memory, it always access a large chunk of memory at once.Even If that thread only needs to read or write a small subset the data in that large chunks, then the GPU can exploit that zand reuse this larger chunk. For all the thread that are trying to access that memory. We say such an access pattern is Global Memory Access

    Greatest Impact

    It is a cost effective alternative with highest achievable performance under the given constraints by maximizing desired factors and minimizing undesired ones. In comparison, maximization means trying to attain the highest or maximum result or outcome without regard to cost or expense.

    Vector Registers

    A Vector processor is a processor that can operate on an entire vector in one instruction. ... In vector-register architecture, operands are read into vector registers from which they are fed to the functional units and results of operations are written to vector registers.

    Row/ Column Major Order

    The elements in row-major order are arranged consecutively along the row and that in the column-major order are arranged consecutively along the column. A general way to order objects with many attributes is to first group and order them by one attribute, and then, within each such group, group and order them by another attribute, etc. If more than one attribute participate in ordering, the first would be called major and minor. If two attributes participate in ordering, it is sufficient to name only the major attribute.

    Peak Bandwidth

    Peak memory bandwidth is simply the maximum theoretical bandwidth the memory system can manage. It\'s seldom hit in reality (if at all) because of other bottlenecks in the systemAs for frames per second, there are lots of reasons, including running without vsync, getting a tighter input response, 120 Hz LCDs, and the fact that excess frames can be converted into higher image quality by raising the detail level.

    Memory Allocations

    Memory allocation is a process by which computer programs and services are assigned with physical or virtual memory space. Memory allocation is the process of reserving a partial or complete portion of computer memory for the execution of programs and processes.


    Dalvik is an open source, register-based virtual machine (VM) that’s part of the Android OS. The Dalvik VM executes files in the Dalvik Executable (.dex) format and relies on the Linux kernel for additional functionality like threading and low-level memory management.


    Compile refers to the act of converting programs written in high level programming language, which is understandable and written by humans, into a low level binary language understood only by the computer. To compile, you need a compiler, which is a software program that converts high level programming language code into machine code.

    Link time

    In computer science, link time refers to the period of time, during the creation of a computer program, in which a linker is being applied to that program. Link time occurs after compile time and before runtime (when a program is executed).

    Drill Down

    In information technology to drill down means to request further information on a specific subject. In a GUI-environment, drilling down may involve clicking on a link or other representation to reveal more detail.Drilling down through a database involves accessing information by starting with a general category and requesting more specific information through successive database queries, with each query informing the next, and increasing data granularity.

    Self Tuning

    A self-tuning system is capable of optimizing its own internal running parameters in order to maximize or minimize the fulfilment of an objective function; typically the maximization of efficiency or error minimization.Self-tuning and auto-tuning often refer to the same concept. Many software research groups consider auto-tuning the proper nomenclature.


    Quicksort is a comparison sort, meaning that it can sort items of any type for which a \"less-than\" relation (formally, a total order) is defined. Efficient implementations of Quicksort are not a stable sort, meaning that the relative order of equal sort items is not preserved. Quicksort can operate in-place on an array, requiring small additional amounts of memory to perform the sorting. It is very similar to selection sort, except that it does not always choose worst-case partition.

    Adaptive Control

    Adaptive control is the control method used by a controller which must adapt to a controlled system with parameters which vary, or are initially uncertain. For example, as an aircraft flies, its mass will slowly decrease as a result of fuel consumption; a control law is needed that adapts itself to such changing conditions. Adaptive control is different from robust control in that it does not need a priori information about the bounds on these uncertain or time-varying parameters; robust control guarantees that if the changes are within given bounds the control law need not be changed, while adaptive control is concerned with control law changing itself.

    PAPI (Performance Application Programming Interface)

    Performance Application Programming Interface (PAPI) is a portable interface (in the form of a library) to hardware performance counters on modern microprocessors. It is being widely used to collect low level performance metrics (e.g. instruction counts, clock cycles, cache misses) of computer systems running UNIX/Linux operating systems. PAPI provides predefined high level hardware events summarized from popular processors and direct access to low level native events of one particular processor. Counter multiplexing and overflow handling are also supported. Operating system support for accessing hardware counters is needed to use PAPI.

    Code Quality

    Different teams may use different definitions, based on context. Good code quality may mean one thing for an automotive developer. And it may mean another for a web application developer.Code quality defines codes that is good. High quality is critical for many development teams today. And it\'s especially important for those developing safety-critical systems.


    In the specification, Flexbox is described as a layout model for user interface design. The key feature of Flexbox is the fact that the items in a flex layout can grow and shrink. Space can be assigned to the items themselves, or distributed between or around the items.Flexbox also enables alignment of items on the main or cross axis, thus providing a high level of control over the size and alignment of a group of items.

    Flex Container

    A flexbox layout is defined using the flex or inline-flex values of the display property on the parent item. This element then becomes a flex container, and each one of its children becomes a flex item.A value of flex causes the element to become a block level flex container, and inline-flex an inline level flex container. These values create a flex formatting context for the element, which is similar to a block formatting context in that floats will not intrude into the container, and the margins on the container will not collapse with those of the items.

    Flex Item

    The direct children of a Flex Container (elements with display: flex or display: inline-flex set on them) become flex items. Continuous runs of text inside flex containers will also become flex items.

    Flex Wraps

    The flex-wrap CSS property sets whether flex items are forced onto one line or can wrap onto multiple lines. If wrapping is allowed, it sets the direction that lines are stacked.


    A so-called website blocker is something that prevents search engines from accessing the site. As a result the website cannot be included in the search engine index and will not appear in the search results. For example, if an entire website is password protected, search engines will be denied access.

    Agile Content Development

    Agile content development is a technology-supported method to develop and continuously optimize competitive content. The methodology revolutionizes the classic linear writing of SEO-optimized content by consistently integrating the users and continually measures the content performance.

    Broken Links

    A defective link is a link that has no object or does not lead to anything. Causes for defective links include programming errors, temporarily unavailable websites or if the address of the site connected to by a link has changed. Defective links diminish the quality of a website and make the job of the crawler more difficult. For these reasons a website with defective links will appear lower down in search results.

    Defective Links

    A defective link is a link that has no object or does not lead to anything. Causes for defective links include programming errors, temporarily unavailable websites or if the address of the site connected to by a link has changed. Defective links diminish the quality of a website and make the job of the crawler more difficult. For these reasons a website with defective links will appear lower down in search results.


    A crawler is a program used by search engines to collect data from the internet. When a crawler visits a website, it picks over the entire website’s content (i.e. the text) and stores it in a databank. It also stores all the external and internal links to the website. The crawler will visit the stored links at a later point in time, which is how it moves from one website to the next. By this process the crawler captures and indexes every website that has links to at least one other website.

    Keyword Proximity

    A search term can be made up of a combination of keywords. The keyword proximity refers to the distance between the search term’s individual keywords. For example: a website contains the keywords that make up the search term “dentist Boston implant” in the heading “Your professional dentist in Boston; dental practice for minimally invasive implants”. The search term proximity between “dentist” and “Boston” is one word, between “Boston” and “implant” it is five words. The smaller the distance between a search term’s individual keywords, the more relevant it will be from a search engine‘s point of view.

    Meta Title

    Every webpage (e.g. homepage, subpage) has its own title. The page title is laid out in HTML code and appears in the title bar of the browser. Search engines display page titles in their search results. In addition, search engines use page titles in order to recognize what information the website contains. Ideally page titles should include the search term for which the website has been optimized.

    Flex Bugs

    Flex Bugs is a community-curated list of Flexbox browser bugs and workarounds.


    When dealing with search engines, the term ‘relevance‘ describes the extent to which the content of a website corresponds to the search term used. The relevance of a website’s content is particularly important for search engines; it affects how high a website will appear in the search results for a given search term.

    Keyword Stuffing

    Keyword stuffing is when someone attempts to manipulate their position in the search results by concentrating on relevant keywords. Search engines can tell when keywords are abnormally distributed throughout the text or in a website’s meta tags. If the same keywords follow one another too closely, the search engine will downgrade the website and it will then appear lower down in search results.

    Keyword Density

    Keyword density tells you how often a search term appears in a text in relation to the total number of words it contains. For example: if a keyword appears three times in a 100 word text the keyword density would be 3%. From the point of view of search engines, a high keyword density is a good indicator of search engine spam. If a keyword appears too often in a website, search engines will downgrade the website and it will then appear lower down in search results.

    Link Juice

    Link juice is slang used to describe and measure how much power a backlink passes onto another site and therefore strengthens it. If a website references another with a link (DoFollow), it transmits its positive properties to an extent (e.g. PageRank, TrustRank) and therefore gives a recommendation from the point of view of the search engine.

    Google Search Console

    The Google Search Console is a free web analysis tool offered by Google. With the tool both websites and apps can be analyzed and monitored. Alongside central information on on page and off page factors, users can also receive notifications about unnatural links, if their website has been hacked or the condition of the registered website or app via the Search Console.

    Content Score

    The content score is an aggregated predictor for the competitiveness of online content. Within the editor of Searchmetrics Content Experience (SCE) the Content Score uses data to determine the quality of the writing and optimization to what is considered to be relevant content.

    Domain Trust

    The domain trust of a website describes its trustworthiness and integrity. There is no single, accepted calculation method for this key figure. Google and providers of SEO software use several metrics to determine domain trust. The quality of the links as well as the quality of the content are considered important elements when calculating the domain trust metric. A high domain trust is considered a ranking advantage in search results.


    Cloaking is a method which gives search engines the impression that a website carries content that is different to what users actually see. Visitors see a user friendly, visually appealing website which may, for example, contain little text and plenty of graphic or multimedia elements.Search engines are limited in their ability to recognize graphic and multimedia elements, which is why they are presented with a different website

    Rich Snippets

    Special result snippets in Google search results are described as rich snippets. They include additional information that is not stored in the meta description of the affected target site, but is stored as structured data in its source code with the help of markups.

    Meta Description

    The meta description is one of a web page’s meta tags. With this meta information, webmasters can briefly sketch out the content and quality of a web page. The page description for a web page is usually displayed when the page for a specific query is listed as a snippet in the SERPs.

    No Follow Attributes

    Links can be provided in HTML code together with a nofollow attribute. This attribute ensures that the search engines cannot follow the link and therefore the link will not be classed as a backlink for the linked website if nofollow backlinks are used exclusively, the linked website will not be included in the index

    Paid Listing

    It is possible to pay a search engine for a placement in certain search results. These advertisements do not appear in natural search results. Instead, they appear in the sponsored results (usually on the right-hand side of search engine’s results page) in response to a corresponding search term. The amount spent on advertising can be adjusted for a variety of factors. In addition, you can determine whether the advertisement appears regionally or nationwide. The fee for these ads is calculated using the number of clicks the advertisement attracts. The higher the advertising budget the better the position the website will get in a given search result.

    Progressive Web Apps

    PWAs, are hybrid websites that bear many characteristics of classic smartphone apps, but that are loaded via a browser. These cross-breeds of traditional websites and mobile apps can be indexed by Google just like any regular website. At the same time, content can be used in the same way as with a native app, and be made available across platforms. In the future, PWAs are likely to play an important role in mobile optimization. PWAs can be traced back to an initiative supported by Google.


    The sitemap.xml file in an XML file that is saved to a website’s server. It contains a list of all the subpages belonging to the website. These files help search engines to learn more about the structure of a website. This speeds up the crawl process and reduces the likelihood that the crawler will overlook subpages. In addition, the file can provide additional information about certain content, e.g.: Information about images or videos that can be found on a website or the duration of a video and its subject. General information about the website, e.g. when it was last updated.

    Use Intent

    The user intent, or search intent states which goal or intention an internet user has when entering a search term into a search engine. User intent is now a central factor in content and search engine optimization and is eclipsing individual keywords as a dominant ranking factor.


    Robots.txt file is a text file that can be saved to a website’s server. It determines if and when the search engine crawlers can visit a website’s subpages and include them in their index. In doing this, certain subpages can be excluded from the search results.

    Server Speed

    Server speed is measured by testing its response time – the amount of time it takes for the server to respond to a request from a client.


    CG or computer graphics are any image media, usually movies and pictures that are created through the use of hardware and software. They are often referred to as computer-generated imagery; more commonly known as CGI. An example of a computer graphic is the picture shown on this page.

    Keyword Canonization

    Additional keywords that are related to approved project include the following terms. They are identified as related because they are used to described pages that the keyword approved project also describes. The following keywords were found on pages linked to pages with approved project assignment to them

    File Sizes

    The size of a file is the amount of space it takes up on your hard drive. The File Size is measured in bytes as opposed to bits. One byte consists of 8 bits. The value is thus given out in bytes, kilobytes (KB), megabytes (MB), gigabytes (GB) and so on. One megabyte is 1024 kilobytes, one kilobyte is 1024 bytes, etc.The display of the File Size might wary by a few bytes depending on the hard drive it is saved on. Some files might take up a little more space on an external drive like a USB stick as compared to on the hard


    Focus is the thinking skill that allows people to begin a task without procrastination and then maintain their attention and effort until the task is complete. Focus helps people pay attention in the midst of distractions and setbacks and to sustain the effort and energy needed to reach a goal.

    Authority Site

    An authority site is a very high quality website that is respected by knowledgeable people in its industry. It is a website that has content on it that is so good and makes the site so useful that people are actually glad they landed on it and want to share it with their friends. Authority sites publish trustworthy information and link to other trustworthy places on the web.

    App Personalization

    App Personalization is the process of building a mobile app to meet the needs of specific audiences. Similar to other forms of personalization, app personalization aims to present user experiences that are customized to their specific needs, rather than a broad, one size fit alls experience for all users.


    Bayesian is a probability concept that interprets probability as a degree of belief. In A/B testing, Bayesian probability offers an absolute level of a test result\'s validity.


    In configuration management, a \"baseline\" is an agreed description of the attributes of a product, at a point in time, which serves as a basis for defining change. A change is a movement from this baseline state to a next state.

    Campaign Scheduling

    Campaign scheduling is a feature that allows the user to start/pause campaigns automatically for certain periods of time. For example, a test campaign that should run only on a specific day of the week. This does not apply to always-on features like Heatmaps and Recordings.

    Churn Rate

    Churn rate is the percentage of customers of a service that discontinue using the service in a specific interval of time. A high churn rate often indicates that a company\'s services are not satisfactory. Churn rate is also known as Attrition Rate.


    Clickbait refers to the sensationalized low-quality content on the internet, whose main purpose is to attract visitors and generate revenue from ad clicks. It is a form of False advertisement which uses hyperlink text or a thumbnail link that is designed to attract attention and entice users to follow that link and read , view or listen to the linked.

    Canonical URL

    A canonical link element is an HTML element that helps webmasters prevent duplicate content issues in search engine optimization by specifying the \"canonical\" or \"preferred\" version of a web page. It is described in RFC 6596, which went live in April 2012.


    Clickstream is the sequence of hyperlinks one or more website visitors follows on a given site, presented in the order viewed.A visitor\'s click path may start within the website or at a separate 3rd party website, often a search engine results page, and it continues as a sequence of successive web pages visited by the user.Click paths take call data and can match it to ad sources, keywords, and/or referring domains, in order to capture data.

    Breadcrumb Navigation

    Breadcrumb Navigation is a form of site navigation that shows visitors where they are on a site\'s hierarchy of pages without having to examine a URL structure. Ecommerce stores with a large number of categories can simplify the user experience by displaying breadcrumbs.

    Cross Domain Tracking

    Cross-domain tracking is the ability of tracking devices to connect sessions from two separate websites domains in an attempt to attribute behavior to the same user.

    Click Area

    A type of insight report classified under website heatmaps that provides numerical data about clicks on various elements opposed to visually representing them as hot-zones.

    Directional Clues

    Directional cues are visual elements of a website that are used to direct visitors’ attention to a specific area on the website (a CTA or an information box).

    Date Range Filter

    Date-range filters is the ability to filter a report for a specific date range. For example, view a Goal’s conversion report when a marketing campaign was live for a week on the website.


    Drop-off is a field-level metric in a form analytics report that shows the number of visitors that dropped-off from filling up the form from that specific field.

    Do Not Track

    Do not track is a browser setting that communicates to websites that visitor’s internet usage should not be tracked by analytics tools, although many websites might still collect some data to improve security, serve relevant ads, and so on.

    Exit pop-up

    Exit pop-up is a pop-up that is displayed on the screens of website visitors as soon as they show an intent to leave the website. Exit pop-ups generally carry some sort of incentive for visitors, encouraging them to engage more with the website.

    Experience Optimization

    Experience optimization is the process of testing and optimizing a website so that visitors get the best possible experience across all touchpoints throughout the website journey.

    Eye Flow

    Eye flow is the study of visitors’ eye movements while browsing a website. Eye flow helps to track areas that visitors view or discard the most.

    Field Level Statistics

    Field level statistics is that part of a form analytics report that provides insights on the performance of individual fields in terms of time spent, refills, ignores, etc.

    Feature Testing

    A Software feature can be defined as the changes made in the system to add new functionality or modify the existing functionality. Each feature is said to have a characteristic that is designed to be useful, intuitive and effective. In reality, a new test set is created for testing that feature corresponding to that cycle of that release. The extremely important and generally used new features ought to be tested thoroughly in each build of that release and also regression testing should be done relevant to those areas.

    Funnel Testing

    Funnel testing is a testing method that involves comparing not just two pages against each other, but multiple pages that are related and are all part of your sales funnel. Funnel tests or multi-page tests work similarly to A/B tests, but instead of changing only some elements of the control page, you create variations of all the original pages in your sales funnel.

    Feature Rollout

    A feature rollout is the software development process of introducing a new feature to a set of users.In the not so recent past, software was rolled out once every week or two, with a number of changes being bundled together, and then monitored. If anything broke, it might necessitate a full roll-back while engineers investigated the issue.


    Gamification is the practice of introducing game-style offers to potential/existing customers. The idea is to encourage them to complete more transactions — in a fun and engaging way. Loyalty program is an example of a gamification strategy.

    Geo Fencing

    Geo-fencing is the practice of targeting users based on their location. It involves using GPS/map technology to create a virtual boundary around a physical location and sending targeted messages to users when they enter the area.

    Geo Targeting

    Geotargeting in geomarketing and internet marketing is the method of determining the geolocation of a website visitor and delivering different content to that visitor based on their location. This includes country, region/state, city, metro code/zip code, organization, IP address, ISP or other criteria.

    Hesitation Time

    Hesitation time is a field-level stat in a form analytics report that shows the time spent by the visitor on the field when they were not actively filling it up.


    Hypothesis is an idea arising from observing behavior patterns of visitors in an attempt to improve the performance of the website. The hypothesis is then tested to prove or disprove it by understanding the impact of the change on goals associated with it.

    JS Variable

    JS variable is a targeting condition that evaluates a custom criteria using javascript variables defined on a page.

    UUID Unique Visitors

    The first time a user arrives at your website and continues to browse. If a visitor with the same IP address comes back at a later point it will not be counted into the number of unique visits.


    Leads are potential customers for a business who have already shown interest by providing their contact information — permitting the company to contact them.

    Null Hypothesis

    Null hypothesis is the hypothesis that an A/B test tries to disprove. The null hypothesis states that the conversion rates of control and variation(s) are the same.

    Qualitative Visitors Research

    Qualitative visitor research involves the use of research tools like heatmaps, session recording, form analysis, and so on to track and analyze visitors’ browsing pattern on a webpage or website based on their real-time behavior. It allows you to gauze beyond just numbers and dive deep into visitors’ behavioral pattern to glean valuable visitor behavior insights.

    Below the fold

    This term is a carry-over from newspaper publishing days. In newspaper terms, “below the fold” means content was on the bottom half of the page (below the physical fold in the paper). In web design terms, “below the fold” refers to the content that is generally going to be below the point first viewable to the average website visitor in their browser (in other words, viewers would have to scroll down to see the content).


    Breadcrumbs are the bit of navigation elements that generally appear near the top of a given web page that shows you the pages and subpages appear before the page you’re on. For example, on a blog, the breadcrumbs might look something like: Home > Category > Year > Month > Post (or they might be a lot simpler that that).

    Content Management System (CMS)

    Also known as a CMS, the Content Management System is a backend tool for managing a site’s content that separates said content from the design and functionality of the site. Using a CMS generally makes it easier to change the design or function of a site independent of the site’s content. It also (usually) makes it easier for content to be added to the site for people who aren’t designers.

    CSS framework

    A CSS framework is a collection of CSS files used as the starting point to make XHTML and CSS web sites quickly and painlessly. They usually contain CSS styles for typography and layout.


    Deprecated code is code that is no longer included in the language specifications. Generally this happens because it is replaced with more accessible or efficient alternatives.


    Stands for Dynamic HyperText Markup Language. DHTML fuses XHTML (or any other markup language), the DOM, JavaScript (or other scripts), and CSS (or other presentation definition languages) to create interactive web content.


    The doctype declaration specifies which version of HTML is used in a document. It has a direct effect on whether your HTML will validate.

    Elastic layout

    An elastic layout is one that uses percentages and ems for widths paired with a max-width style to allow the site layout to stretch when font sizes are changed. It’s ability to flex to accommodate the browser width and reader’s font preferences are where it gets its name.


    In XML, an element is the central building block of any document. Individual elements can contain text, other elements, or both.


    EM is a unit of measurement for sizing fonts and other elements within a web page relative to the item’s parent element. A 1em font is equal to the point size for the font already defined in the parent element (2em would be twice the current size; .5em would be half the current size).

    Embedded style

    An embedded style is a CSS style written into the head of an XHTML document. It only affects the elements on that page, instead of site-wide as a separate CSS file does. Style in an embedded style sheet will override styles from the linked CSS file.


    This is a CSS document that is written in a separate, external document. The biggest advantage to using an external style sheet is that it can be linked to by multiple HTML/XHTML files (which means changes made to the style sheet will affect all the pages linked to it without having to change each page individually).


    Favicons are tiny (generally 16x16 pixels, though some are 32x32 pixels), customizable icons displayed in the web address bar in most browsers next to the web address. They’re either 8-bit or 24-bit color depth and are saved in either .ico, .gif or .png file formats.


    A fixed width layout has a set width (generally defined in pixels) set by the designer. The width stays the same regardless of screen resolution, monitor size, or browser window size. It allows for minute adjustments to be made to a design that will stay consistent across browsers. Designers have more control over exactly how a site will appear across platforms with this type of layout.


    The focal point of a website is the spot on a web page that they eye is naturally drawn to. This could be an image, a banner, text, Flash content, or just about anything else. You want to make sure that whatever is acting as your focal point is the most important part of your site.


    The fold is a term carried over from newspaper design and pagination (where the fold referred to the physical fold in the paper). The fold in a website is the point on the webpage that rests at the bottom of someone’s browser (in other words, to see anything below the fold, they would have to scroll down). There are varying opinions on how important the fold is in web design.


    Font family is a group designation for defining the typefaces used in CSS documents. The font family tag generally lists multiple fonts to be used, and usually ends with the generic font category (such as “serif” or “sans-serif’).


    Also referred to a “hex” numbers, they are a base-16 numbering system used to define colors online. Hex numbers include the numerals 0-9 and letters A-F. Hexadecimal numbers are written in three sets of hex pairs. Because screen colors are RGB (Red, Green, Blue), the first pair defines the red hue, the second pair defines the green hue, and the third pair defines the blue.


    Contrary to popular belief, a hit does not represent a single visitor to a website. A hit is actually a request for a single file from your web server. This means one page can actually generate multiple hits, as each page generally has more than one file (an html or other base file, a css file, multiple images, etc.) and each one is requested from the server whenever the page is loaded. Some marketing people like to quote hits to unknowing consumers as the number makes their site sound like it’s getting a whole lot more traffic than it actually is.


    The .htaccess file is the default directory-level configuration file on Apache servers. They are also known as “distributed configuration files.” Configuration directives contained in the .htaccess file apply to the directory in which the file is placed as well as all of its subdirectories. Within the .htaccess file things like authorization and authentication, rewriting of URLs, cache control and customized error responses can all be specified.


    Also referred to as an HTML element, an HTML tag is the bit of code that describes how that particular piece of the web page it’s on is formatted. Typical tags specify things like headings, paragraphs, links, and a variety of other items.


    A hyperlink is a link from one web page to another, either on the same site or another one. Generally these are text or images, and are highlighted in some way (text is often underlined or put in a different color or font weight). The inclusion of hyperlinks are the “hyper” part of “hypertext.”


    Hypertext is any computer-based text that includes hyperlinks. Hypertext can also include presentation devices like tables or images, in addition to plain text and links.

    RPV (Revenue Per Visitor )

    Revenue per visitor or RVP is the average revenue that a website earns from each of its visitors. RPV is considered as the most appropriate metric that is used to measure an ecommerce store’s performance.


    Scarcity is a psychological tactic that marketers use to push visitors towards a conversion action. It takes advantage of the human fear of \'shortage\' or in today\'s terms, FOMO (fear of missing out) - “Only 5 items left” and “Sale only till 8 PM” are some examples where scarcity marketing is used.

    Server Site Testing

    Server Site Testing is the practice of testing variations by directly rendering them on the server itself to a defined audience segment. This is most suitable for testing product features before rolling them out to the entire audience base.

    Split Url Testing

    Split URL testing involves testing multiple versions of a webpage that are hosted on different URLs. Split URL testing is best suited when there are major design changes on the web page.

    Standard Error

    The degree to which the result of an A/B test can be apart from the actual figure is called standard error.

    Scroll Map

    Scrollmap is a type of website heatmap that visually represents visitors’ scrolling behavior on a webpage. It indicates how far users scroll down a page as well as which sections they spend the most time in.

    Title Tag

    Title tag is an HTML tag — a part of meta tags — that defines the title of a web page. A web page\'s title tag is displayed above its meta description in SERPs.

    Test Hypothesis

    Test hypothesis is a tentative assumption that changing a specific element(s) of a website will lead to higher number of conversions. Establishing a test hypothesis is the first step towards executing an A/B test.

    Trust Badges

    Trust badges are small logos or icons that convince visitors about the safety and credibility of the website.

    Test Duration

    Test duration is the specific time period over which an A/B test is run. It is imperative to determine the minimum test duration of an A/B test for reaching a conclusive result.

    User Testing

    User testing is the practice of testing the usability of a website with the help of real people. User testing can be done in the following ways: 1. By inviting potential users to use your website, and observing the problem areas in usability. 2. By evaluating a website based on the behavior of real visitors — using tools like clickmaps and heatmaps.

    User Generated Content

    User generated content is content in the form of text, images, and videos that are submitted by users to a website as a part of some campaign.


    Whitespace is a design strategy which involves using blank spaces for directing attention towards a valuable website elements such as a CTA.


    A software widget is a relatively simple and easy-to-use software application or component made for one or more different software platforms. A desk accessory or applet is an example of a simple, stand-alone user interface, in contrast with a more complex application such as a spreadsheet or word processor.

    Z Index

    Z-index is a css parameter that measures how elements are stacked when they overlap.

    Hreflang Attribute

    Hreflang is an HTML or tag attribute that tells search engines the relationship between pages in different languages on your website. Google uses the attribute to serve the correct regional or language URLs in its search results based on the searcher\'s country and language preferences.


    Infographics are graphic visual representations of information, data, or knowledge intended to present information quickly and clearly. They can improve cognition by utilizing graphics to enhance the human visual system\'s ability to see patterns and trends.


    On the web, interstitials are web pages displayed before or after an expected content page, often to display advertisements or confirm the user\'s age. Most interstitial advertisements are delivered by an ad server.

    Keyword Cannibalization

    Keyword cannibalization is something to take seriously as it can potentially damage your rankings for multiple reasons. Keyword cannibalization happens when a website\'s information architecture relies on a single keyword or phrase on multiple parts of the website.

    Keyword Stemming

    Keyword stemming is a useful tool for web pages and search engine optimization. The process of keyword stemming involves taking a basic but popular keyword pertaining to a particular website and adding a prefix, suffix, or pluralization to make the keyword into a new word.

    Link Farm

    On the World Wide Web, a link farm is any group of websites that all hyperlink to every other site in the group. In graph theoretic terms, a link farm is a clique. Although some link farms can be created by hand, most are created through automated programs and services.

    Link Hoarding

    Link hoarding is a tactic used by some websites as a means to keep one\'s own link popularity by not linking out to others. Some sites may also get around providing a clear outbound link by embedding in JavaScript or using a redirect that doesn\'t link directly to another website.


    Usability is the ease of use and learnability of a human-made object such as a tool or device. In software engineering, usability is the degree to which a software can be used by specified consumers to achieve quantified objectives with effectiveness, efficiency, and satisfaction in a quantified context of use.

    Search Term

    A word or combination of words or characters entered into a search engine in order to specify a particular thing to be searched for on the World Wide Web, over a computer network, or in a database.

    Search Term Registration

    When you register a website with a search engine, you provide the information concerning it to the search engine in order to get it included in the index. The search engine will usually provide a form you fill in for this purpose. Registration can be done manually or automatically. The Google search engine does not require an explicit registration because the it is able to identify new websites on its own through its algorithms.

    Search Engine Spam

    Excessive manipulation to influence search engine rankings, often for pages which contain little or no relevant content.Search engine spamming often gets confused with legitimate search engine optimization (SEO). While there is much gray area between the two extremes, in their most clear cut forms the terms are very different. Spamming involves getting a site more exposure than it deserves for its keywords, leading to unsatisfactory search experiences. Optimization involves getting a site the exposure it deserves on the most targeted keywords, leading to satisfactory search experiences.

    Meta Search Term

    A metasearch engine (or aggregator) is a search tool that uses another search engine\'s data to produce its own results from the Internet. Metasearch engines take input from a user and simultaneously send out queries to third party search engines for results.


    Short for Inline Frame. An iframe is used to display one or more web pages within another normal web page (one that isn’t a frameset page).


    An image map is used in XHTML to allow different parts of an image to become different clickable elements (and can also allow some portions of the image to have no clickable element).


    Stands for Linux, Apache, MySQL, and PHP (or sometimes Perl or Python), and is referring to the specifications of a web server (defining the operating system, web server, database, and scripting language, in that order). One of the advantages of LAMP setups is that the software used is all free and open source.


    A liquid layout is one that is based on percentages of the browser window’s size. The layout of the site will change with the width of the browser, even if the visitor changes their browser size while viewing the page. Liquid layouts take full advantage of a person’s browser width, optimizing the amount of content you can fit on screen at one time.


    Navigation refers to the system that allows visitors to a website to move around that site. Navigation is most often thought of in terms of menus, but links within pages, breadcrumbs, related links, pagination, and any other links that allow a visitor to move from one page to another are included in navigation.


    Nesting refers to putting one HTML element within another element. When this is done, the elements have to be closed in the reverse order from how they were opened.


    A non-breaking space (also referred to as  ) is a white-space character that isn’t condensed by HTML. It’s primary function is to hold open table cells or add spacing between words (or a the beginning of paragraphs if an indent is desired).


    A pageview is a request for an entire web page document from a server by a visitor’s browser. In other words, for each page view your site had, someone (or a search engine spider) looked at that page.


    Short for “permanent link.” Generally used only on blogs, a permalink is a link that is the permanent web address of a given blog post. Since most blogs have constantly-changing content, the permalink offers a way for readers to bookmark or link to specific posts even after those posts have moved off the home page or primary category page.


    A plug-in is a bit of third party code that extends the capabilities of a website. It’s most often used in conjunction with a CMS or blogging platform. Plug-ins are a way to extend the functionality of a website without having to redo the core coding of the site. Plugins can also refer to bits of third-party software installed within a computer program to increase its functionality.


    A pseudo-element is an element used to add a special effect to certain selectors.


    Like pseudo-elements, pseudo classes are used to add special effects to certain CSS selectors.


    Also referred to as RSS. RSS is a standardized XML format that allows content to be syndicated from one site to another. It’s most commonly used on blogs. RSS also allows visitors to subscribe to a blog or other site and receive updates via a feed reader.


    Generally refers to a portion of code on an HTML page that makes the page more dynamic and interactive. Scripts can be written in a variety of languages, including JavaScript.


    In semantic markup, content is written within XHTML tags that offer context to what the content contains. Basic semantic markup refers to using items like header and paragraph tags, though semantic markup is also being used to provide much more useful context to web pages in an effort to make the web as a whole more semantic.


    Stands for Standard Generalized Markup Language. It’s a markup language used for defining the structure of a document. SGML isn’t mentioned very often, but it’s a markup language that serves as the basis for both XML and HTML.


    Stands for Simple Object Access Protocol. It’s an XML-based protocol exchanging information across the internet to allow an application on one site to access an application or database on another site.


    A tag is a set of markup characters that are used around an element to indicate its start and end. Tags can also include HTML or other code to specify how that element should look or behave on the page. See also HTML Tag.


    A template is a file used to create a consistent design across a website. Templates are often used in conjunction with a CMS and contain both structural information about how a site should be set up, but also stylistic information about how the site should look.


    Valid web pages are those that return no errors based on the type of HTML/XHTML specified in the doctype declaration at the beginning of the file. In other words, the code used on the page conforms to the specifications for that version of HTML/XHTML. This can be checked through various validation services, most commonly the one from W3C.

    Synthetic monitoring

    Synthetic monitoring tests a site’s performance in a simulated and consistent environment. This includes running a performance tool as part of the build, or using a tool to run automated (webpagetest.org) tests against a site.

    First meaningful paint

    First meaningful paint is a browser-supplied metric that measures how long it takes for the most meaningful content to be fully rendered on the site. Measurement involves watching all layout events as the page loads, filtering by events for new objects above the page fold, and then accounting for web font loading.

    Input latency

    Input latency is the amount of time it takes for the app to respond to the users as they interact with it. It’s very different than the other metrics, as it doesn’t relate to the initial load and displaying of the page; it’s a metric that is constantly being tracked over time, as the user interacts with the site.

    Render start

    Render start is the time from the first byte to when the browser draws the first pixel on the screen. It is a synthetic metric, as there’s no way to get the metric from the browser itself. It is closely related to first paint, but it’s more accurate because it’s calculated via visual cues. It’s also harder to test than first paint because it requires screen capturing.

    First paint

    First paint is a browser-based metric supplied that indicates the amount of time from first byte to the first pixel rendered. Unfortunately, this metric is inaccurate in some browser implementations, and some report the event too early, before anything has been rendered to the screen. Due to these limitations, it should be used with care. The main reason to use first paint over the more accurate render start is its ease of use in real time user monitoring, as it’s available in most browsers.

    Total page weight

    This metric, also called “total requests”, is an accrual of all a site’s resource weights, measured in kilobytes or megabytes, including the HTML of the page itself. It’s useful for setting weight budgets on a site, which are easy to pass to developers and designers. It doesn’t always tell the whole story of performance, as performance often depends on how a page loads those requests.

    Number of requests

    The number of requests is the total number of requests that the page makes while loading resources such as CSS, JS, fonts, and images. This metric is much less important when the site is served over HTTP/2 because that protocol does not limit the number of concurrent requests. (Each file is requested individually over HTTP 1.x, and browsers limit the number of concurrent requests from each domain.) It’s important to know whether the site requests resources from multiple domains when measuring total number of requests, as the number of domains can impact how the browser can processes these requests in parallel.

    DOM Nodes

    The number of DOM nodes is a rough measure of the amount of HTML content on the page. It refers to how many elements or tags (


    , , etc.) the page contains. While the number of DOM nodes doesn’t affect network performance, it does affect browser performance. A browser will take a longer time to parse, process, and render a page if it has more nodes.


    Also called a unique visitor; visitor is an individual visiting a website during a period of time

    Returning visitor

    Returning visitor is a visitor who can be identified with multiple visits, through cookies or authentication.

    Site audit

    Site audit is the process of reviewing a website and assessing its performance on a variety of criteria. There are several types of site audits, including security audits, SEO audits, competitive audits, and more.


    Uptime is a measure of how long a site is viewable and useable. Downtime on a site may translate into poor customer experience and lost revenue.

    Crawler error

    Crawler error is the inability of a crawler to view or index pages on a website.

    Dead end page

    Pages that include no links and require a visitor to click the back button in order to stay on a website. Dead end pages make is difficult for visitors to navigate a website and, as a result, visitors may be more inclined to exit the site.

    Duplicate content

    When multiple URLs serve the same page. Duplicate content across different URLs on a website leads to poor placement in the search results because they waste search engine resources by collecting and processing identical content. Common types of duplicate pages are printable or text-only versions of the main page, or redirects to login pages intended for your site’s visitors that also return a “You must log in” page to crawlers.


    Measurements that indicate a specific performance metric and allows comparison of metrics between like applications, websites, or companies


    A measure of how easy it is for visitors and search engine crawlers to find that they are looking for on your site. A well-linked, well-structured site has great reachability, and will be evaluated as important by the search engines.


    A website’s ability to retain visitors, measured as a number of pages visited per session and minutes per visit (time on site). Stickiness can be achieved through unique, quality content that visitors find valuable, well-structured pages, and appropriately linked resources.

    Competitive intelligence

    In general, the act of defining, gathering, analyzing, and distributing intelligence about competitors in order to make strategic decisions that ideally lead to competitive advantage in the marketplace.

    Entry page

    The first page that a visitor arrives at on a website from another domain.

    Exit page

    The last page that a visitor accesses during a visit before leaving a website.

    Minutes per visit (time on site)

    The average length of a visit to a website during a selected time period.


    A record of a single visitor browsing a website during a given time period. This can include multiple screen or pageviews, events, or ecommerce transactions. Sessions end at midnight on the day a session was initiated or after 30 minutes of inactivity.

    Social referrals

    A count of all referrals from social networks during a selected time period.

    Performance testing

    Software Performance testing is a type of testing performed to determine the performance of a system to major the measure, validate or verify quality attributes of the system like responsiveness, Speed, Scalability, Stability under a variety of load conditions. The system is tested under a mixture of load conditions and check the time required responding by the system under varying workloads. Software performance testing involves the testing of an application under test to ensure that the application is working as expected under a variety of load conditions. The goal of performance testing is not only finding the bugs in the system but also eliminate the performance bottlenecks from the system.

    Load testing

    Load Testing is basically checking how much traffic your software can handle and take into account its response. We do this test to determine the system\'s ability to handle anticipated peak load conditions and normal conditions. Load Testing helps us to identify the bottlenecks in our systems. This helps us to fix our systems so that when the users access the system they wouldn’t have to face any drawbacks when the traffic is high once the system is live. A typical load test tool records the test while the user performs the steps and generates a script using a script recorder, this is then replayed to test the system by increasing the no. of users accessing the system simultaneously changing parameters.

    Stress testing

    A type of performance testing conducted to evaluate a system or component at or beyond the limits of it’s anticipated or specified workloads, or with reduced availability of resources such as access to memory or servers. Stress testing is a type of performance test designed to evaluate an application’s behavior when it is pushed beyond normal or peak load conditions. The goal of stress testing is to reveal application bugs that surface only under high load conditions. These bugs can include such things as synchronization issues, race conditions, and memory leaks. Stress testing enables you to identify your application’s weak points and shows how the application behaves under extreme load conditions.

    Application stress testing

    This type of test typically focuses on more than one transaction on the system under stress, without the isolation of components. With application stress testing, you are likely to uncover defects related to data locking and blocking, network congestion, and performance bottlenecks on different components or methods across the entire application. Because the test scope is a single application, it is common to use this type of stress testing after a robust application load-testing effort, or as the last test phase for capacity planning. It is also common to find defects related to race conditions and general memory leaks from shared code or components.

    Transactional stress testing:

    Transactional stress tests aim at working at a transactional level with load volumes that go beyond those of the anticipated production operations. These tests are focused on validating behavior under stressful conditions, such as high load with same resource constraints when testing the entire application. Because the test isolates an individual transaction or group of transactions, it allows for a very specific understanding of throughput capacities and other characteristics for individual components without the added complication of inter-component interactions that occurs in testing at the application level. These tests are useful for tuning, optimizing, and finding error conditions at the specific component level.

    Systemic stress testing

    In this type of test, stress or extreme load conditions are generated across multiple applications running on the same system, thereby pushing the boundaries of the applications’ expected capabilities to an extreme. The goal of systemic stress testing is to uncover defects in situations where different applications block one another and compete for system resources such as memory, processor cycles, disk space, and network bandwidth. This type of testing is also known as integration stress testing or consolidation stress testing. In large-scale systemic stress tests, you stress all of the applications together in the same consolidated environment. Some organizations choose to perform this type of testing in a larger test lab facility, sometimes with the hardware or software vendor’s assistance.

    Volume testing

    Volume testing is a non-functional Performance Testing, where the software is subjected to a huge volume of data. It is also referred as flood testing. Volume testing is done to analyze the system performance by increasing the volume of data in the database. With the help of Volume testing, the impact on response time and system behavior can be studied when exposed to a high volume of data.

    Performance tuning

    As performance bottlenecks are identified during load testing and performance testing, these issues are commonly rectified through a process of performance tuning. Performance tuning can involve configuration changes to hardware, software and network components. A common bottleneck is the configuration of the application and database servers. Performance tuning can also include tuning SQL queries and tuning an applications underlying code to cater for concurrency and to improve efficiency. Performance tuning can result in hardware changes being made. This is the last resort; ideally tuning changes will result in a reduction of resource utilization.

    Session management

    Session management is the process of securing multiple requests to a service from the same user or entity. In many cases, a session is initialized by authenticating a user or entity with factors such as a password. Once the user is authenticated, subsequent requests authenticate the session as opposed to the user themselves.

    Session ID

    A session ID is a unique number that a Web site’s server assigns a specific user for the duration of that user’s visit (session). The session ID can be stored as a cookie, form field, or URL (Uniform Resource Locator). Every time an Internet user visits a specific Web site, a new session ID is assigned. Closing a browser and then reopening and visiting the site again generates a new session ID. However, the same session ID is sometimes maintained as long as the browser is open, even if the user leaves the site in question and returns. In some cases, Web servers terminate a session and assign a new session ID after a few minutes of inactivity (timeout).

    Simultaneous users

    Simultaneous users are the users who send requests at the same time to the target.

    Endurance (Soak) testing

    Endurance Testing is a type of performance test that verifies a system’s stability and performance characteristics over an extended period of time. It is typical in this type of performance test to maintain a certain level of user concurrency for an extended period of time. This type of test can identify issues relating to memory allocation, log file handles, and database resource utilization. Endurance testing is a subset of load testing. An endurance test is a type of performance test focused on determining or validating the performance characteristics of the product under test when subjected to workload. The execution time duration can be set in the schedule section in JMeter thread groups.

    Spike testing

    Spike testing is a type of load test. The object of this type of performance test is to verify a system’s stability during bursts of the concurrent user and or system activity to varying degrees of load over varying time periods. A spike test is a type of performance test focused on determining or validating performance characteristics of the product under test when subjected to workload models and load volumes that repeatedly increase beyond anticipated production operations for short periods of time. Spike testing is a subset of stress testing. Spike testing is a subset of stress testing. A spike test is a type of performance test focused on determining or validating the performance characteristics of the product under test when subjected to workload models and load volumes that repeatedly increase beyond anticipated production operations for short periods of time. Synchronizing timer can be used for simulating the spikes in JMeter. The purpose of the SyncTimer is to block threads until X number of threads have been blocked, and then they are all released at once. A SyncTimer can thus create large instant loads at various points of the test plan.

    Baseline testing

    Creating a baseline is the process of running a set of tests to capture performance metric data for the purpose of evaluating the effectiveness of subsequent performance-improving changes to the system or application. A critical aspect of a baseline is that all characteristics and configuration options except those specifically being varied for comparison must remain invariant. Once a part of the system that is not intentionally being varied for comparison to the baseline is changed, the baseline measurement is no longer a valid basis for comparison.

    Benchmark testing

    Benchmarking is the process of comparing your system’s performance against a baseline that you have created internally or against an industry standard endorsed by some other organization.


    The capacity of a system is the total workload it can handle without violating predetermined key performance acceptance criteria.

    Capacity testing

    A capacity test complements load testing by determining your server’s ultimate failure point, whereas load testing monitors result at various levels of load and traffic patterns. You perform capacity testing in conjunction with capacity planning, which you use to plan for future growth, such as an increased user base or increased volume of data. For example, to accommodate future loads, you need to know how many additional resources (such as processor capacity, memory usage, disk capacity, or network bandwidth) are necessary to support future usage levels. Capacity testing helps you to identify a scaling strategy in order to determine whether you should scale up or scale out.


    Investigation is an activity based on collecting information related to the speed, scalability, and/or stability characteristics of the product under test that may have value in determining or improving product quality. Investigation is frequently employed to prove or disprove hypotheses regarding the root cause of one or more observed performance issues.

    Component testing

    A component test is any performance test that targets an architectural component of the application. Commonly tested components include servers, databases, networks, firewalls, clients, and storage devices.

    Smoke testing

    A smoke test is the initial run of a performance test to see if your application can perform its operations under a normal load.

    Return Of Investments (ROI)

    ROI stands for return on investment. The return on investment measures or compares the benefit of an investment to what you would have without making that investment. ROI is expressed as a percentage. ROI includes your profits from your business, which is the amount of money you have left after expenses. One way to calculate your return on investment is to divide your gain from the investment by the cost of the investment. The higher the percentage is, the better the return.

    Unit test

    In the context of performance testing, a unit test is any test that targets a module of code where that module is any logical subset of the entire existing code base of the application, with a focus on performance characteristics. Commonly tested modules include functions, procedures, routines, objects, methods, and classes. Performance unit tests are frequently created and conducted by the developer who wrote the module of code being tested

    Behavioral Targeting

    Behavioral targeting is a technique in advertising, whereby an ad is placed in a specific online location based on the behavior of the users who spend time at that location. This tool is primarily used by advertisers and marketing managers in order to improve the effectiveness of their ads.

    CPL (Cost Per Lead)

    Also known as cost per lead, CPL is a pricing model for online advertising where advertisers will pay for every customer that fills out a lead or sign-up form. In CPL campaigns, advertisers can also pay for contact information of targeted consumers who show interest in their service or product. They are mostly used by direct-response marketers and brand marketers.

    Custom Variables

    These are pair tags that can be inserted in tracking code for the purpose of adjusting and customizing your Google Analytics tracking. They make it possible for you to define extra segments to apply to your users other than those provided by default by Google Analytics.

    Enhanced Ecommerce Report

    Enhanced Ecommerce Reports (EER) is a feature available in the Universal Analytics version of Google Analytics. EER allows for using GA to track many more features than just regular Ecommerce reports, including the ability to measure refunds. By using EER you can gain a more accurate understanding of how your company is doing precisely

    Event Tracking

    Event tracking is a method that is available in Google Analytics. It lets you record user interactions with various web elements like a menu system driven by Flash. You can do this by attaching a piece of code to an element in the website.

    Flow Visualization

    Flow visualization is a graphic that tracks the actual pathways that a person has taken through the funnel. The graphic even includes where and when they left the funnel assuming they did not complete a purchase. These are helpful to determine the place of exit as well as the reason for the exit, so that you can tweak and modify trouble areas within your goal funnel.

    Goal Funnels

    A goal funnel is a series of web pages that lead up to a goal. Google analytics offers goal funnel visualization reports. These are extremely beneficial when analyzing your funnels because it saves time and takes away the majority of the labor involved.

    Social Logins

    Social logins are buttons produced by social media platforms such as Facebook, Twitter and Linkedin that allow users to login to your website using their already made profile with the press of a single button. Using social logins can be an advantage because it lowers the barrier of entry, if they’re already logged in to a social network. People like one step funnels that allow them to quickly log in and out. Putting social login buttons in a prominent place can also be useful for trust purposes, since people trust the networks they are already a part of.

    Quality Assurance

    This is an abbreviation used for quality assurance. This is a mechanism used by companies and businesses to prevent damage or defects in manufactured products. It involves testing your product before selling it to customers. Learn how to QA your UX designs.

    Mobile Site

    A mobile site is a version of your web page optimized for Mobile Traffic. The input is touch screen, so there is no mouse hovering (although many new laptops also have touch screens, so maybe consider leaving out things that require mouse hovering in general). Many mobile sites are viewed through applications instead of web browsers, so users may not have easy access to your URL. For this reason it is very helpful to make prominent share buttons so users can share your site with others.

    Validation test

    A validation test compares the speed, scalability, and/or stability characteristics of the product under test against the expectations that have been set or presumed for that product.

    Ramp up period

    Ramp up period defines how long JMeter should take to get all the threads started. If there are 10 threads and a ramp-up time of 100 seconds, then each thread will begin 10 seconds after the previous thread started, for a total time of 100 seconds to get the test fully up to speed. Ramp Up period can be defined in the Thread Groups.

    Ramp down period (Shutdown time)

    Ramp-down is the amount of time taken for stopping the threads. Ramp down cannot be defined in normal thread groups coming with JMeter. It is possible to define the ramp down in thread groups installed from JMeter plugins. E.g Ultimate Thread Group.


    Workload is the stimulus applied to a system, application, or component to simulate a usage pattern, in regard to concurrency and/or data inputs. The workload includes the total number of users, concurrent active users, data volumes, and transaction volumes, along with the transaction mix. For performance modeling, you associate a workload with an individual scenario.

    Distributed (Remote) testing

    Distributed Testing is a kind of testing which use multiple systems to perform Stress Testing. Distributed testing is applied for testing websites and server applications when they are working with multiple clients simultaneously. Distributed testing is used when the single JMeter engine cannot create the required number of virtual users (threads) for the test.

    Agent (Slave)

    The test agents are used to run the tests and collect data including system information and response time information behalf of the test controllers. Jmeter server (jmeter-server.bat) work as load generating agents. The test agent runs as a service that listens for requests from the test controller to start a new test. When the test agent receives a request, the test agent service starts a process on which to run the tests. Each test agent runs the same test plan.


    The Master or test controller is used to administering the test agents and collect test results. The test controller provides a general architecture for running tests and includes special features for running load tests. The test controller sends the load test to all test agents and waits until all the test agents have initialized the test. When all test agents are ready, the test controller sends a message to the test agents to start the test.

    Stop test

    Stop a test gracefully completing the samplers being processed.

    Shutdown test

    Stop a test abruptly (immediately) without processing the samplers being processed.

    MIME type

    MIME stands for “Multipurpose Internet Mail Extensions. It’s a way of identifying files on the Internet according to their nature and format.

    Think time (user delay)

    Delays that occur while users view content on Web pages — also commonly known as think times — represent the answers to questions such as “How long does it take a user to enter their login credentials?” and “How much time will users spend reading this page?” You can use several different methods to estimate think times associated with user activities on your Web site. The best method, of course, is to use real data collected about your production site. This is rarely possible, however, because testing generally occurs before the site is released to production. This necessitates making educated guesses or approximations regarding activity on the site.


    Samplers perform the actual work of JMeter. Samplers send requests to the target. Each sampler (except Test Action) generates one or more sample results. The sample results have various attributes (success/fail, elapsed time, data size etc.) and can be viewed in the various listeners.

    Logic controllers

    Logic Controllers determine the order in which Samplers are processed. They can be used for conditional execution of the samplers in the context. Samplers are executed sequentially when logic controllers are not used.


    Listeners collect the test results and make them available for the users to view, save or read the same test results.

    Configuration elements

    Configuration elements can be used to set up defaults and variables for later use by samplers. Note that these elements are processed at the start of the scope in which they are found, i.e. before any samplers in the same scope.


    Assertions are used to perform additional checks on samplers and are processed after every sampler in the same scope. To ensure that an Assertion is applied only to a particular sampler, add it as a child of the sampler.


    Timers are used for pausing the samplers before sending the requests. Timers work in conjunction with the samplers. A timer which is not in the same scope as a sampler will not be processed at all. Timers are used for simulating the user delays (thinking time of the users) in JMeter.


    Preprocessors are used to modify the Samplers in their scope. Preprocessors are applied before the samplers in the scope.


    Post-Processors are applied after samplers. They are applied to all the samplers in the same scope, so to ensure that a post-processor is applied only to a particular sampler, add it as a child of the sampler. Postprocessors are used for extracting the session IDs from the responses and use them in subsequent samplers (requests) in web applications testing.


    Proxy server is a server that acts as an intermediary for requests from clients ( Web browser ) seeking resources from other servers (web server). The HTTP(s) Test Recorded recorder in JMeter is implemented as an HTTP(S) proxy server. You need to set up your browser use the proxy for all HTTP and HTTPS requests.

    JMeter variables

    JMeter variables are available to individual threads. They are not shared with the threads.

    JMeter properties

    JMeter properties are shared through threads. JMeter properties defined in property files can be accessed through any test plan. System properties can be overwritten by the JMeter properties. The properties present in jmeter.properties or reportgenerator.properties should be set in the user.properties file. These properties are only taken into account after restarting JMeter as they are usually resolved when the class is loaded. The Property Display shows the values of System or JMeter properties. Values can be changed by entering new text in the Value column. Properties are common to all threads and need to be referenced using the __P or __property function. JMeter processes function and variable references before passing the script field to the interpreter, so the references will only be resolved once. Variable and function references in script files will be passed verbatim to the interpreter, which is likely to cause a syntax error. props.get(“START.HMS”); props.put(“PROP1″,”1234”);

    System properties

    System properties are commonly used by any Java application. Apache JMeter is a pure Java application hence it inherits all default properties and has the capability to access and override them.

    User properties

    A custom user defines properties can be defined in user.properties file. The values, specified in user.properties file override corresponding values from jmeter.properties file.


    Metrics are measurements obtained by running performance tests as expressed on a commonly understood scale. Some metrics commonly obtained through performance tests include processor utilization over time and memory usage by the load.

    Network-specific metrics

    This set of metrics provides information about the overall health and efficiency of your network, including routers, switches, and gateways. System-related metrics. This set of metrics helps you identify the resource utilization on your server. The resources being utilized are the processor, memory, disk I/O, and network I/O.

    Platform-specific metrics

    Platform-specific metrics are related to software that is used to host your application, such as the Microsoft .NET Framework common language runtime (CLR) and ASP.NET-related metrics.

    Application-specific metrics

    These include custom performance counters inserted in your application code to monitor application health and identify performance issues. You might use custom counters to determine the number of concurrent threads waiting to acquire a particular lock or the number of requests queued to make an outbound call to a Web service.

    Service-level metrics

    These metrics can help to measure overall application throughput and latency, or they might be tied to specific business scenarios.

    Business metrics

    These metrics are indicators of business-related information, such as the number of orders placed in a given timeframe.

    Performance acceptance criteria

    Identify the response time, throughput, and resource utilization goals and constraints. In general, response time is a user concern, throughput is a business concern, and resource utilization is a system concern. Additionally, identify project success criteria that may not be captured by those goals and constraints; for example, using performance tests to evaluate what combination of configuration settings will result in the most desirable performance characteristics.

    Implement test design

    Develop the performance tests in accordance with the test design

    Execute the tests

    Run and monitor your tests. Validate the tests, test data, and results collection. Execute validated tests for analysis while monitoring the test and the test environment.


    In the context of performance testing, a scenario is a sequence of steps in your application. A scenario can represent a use case or a business function such as searching a product catalog, adding an item to a shopping cart, or placing an order.

    Testing environment

    The test environment includes the physical test environment and the production environment as well as the tools and resources available to the test team. The physical environment includes hardware, software, and network configurations. Having a thorough understanding of the entire test environment at the outset enables more efficient test design and planning and helps you identify testing challenges early in the project. In some situations, this process must be revisited periodically throughout the project’s lifecycle.

    Configure test environment

    Prepare the test environment, tools, and resources necessary to execute each strategy as features and components become available for test. Ensure that the test environment is instrumented for resource monitoring as necessary.

    Staging environment

    Staging is an environment for final testing immediately prior to deploying to production. It seeks to mirror the actual production environment as closely as possible and may connect to other production services and data, such as databases.

    Production environment

    The production environment is also known as live, particularly for servers, as it is the environment that users directly interact with. Performance tests should not be executed against the production environment unless there is a specific reason to do.

    Dynamic data

    Dynamic data is data that is changed when information is updated. For example, session variables connected to authentication mechanisms. This affects website recording, as JMeter needs to know how to capture this dynamic data and reuse it in subsequent requests. Otherwise, playing back the recording will show many errors. This is where Correlations come in. Correlations are the fetching of dynamic data from preceding requests and posting it to subsequent requests. In JMeter, various post-processors can be used for extracting the dynamic data from responses and used in subsequent requests.

    Memory leaks

    Failure to release reachable memory which is no longer needed for your program to function correctly.

    Minimum time

    In JMeter: The lowest elapsed time for the samples with the same label

    Maximum time

    In JMeter: The longest elapsed time for the samples with the same label


    A mean or average response time is the sum of individual response time divided by the number of responses.


    Percentile is the value below which a percentage of data falls. A percentile is a straightforward concept that is easier to demonstrate than define. For example, to find the 95th percentile value for a data set consisting of 100 page-response-time measurements, you would sort the measurements from largest to smallest and then count down six data points from the largest. The 6th data point value represents the 95th percentile of those measurements. For the purposes of response times, this statistic is read “95 percent of the simulated users experienced a response time of [the 6th-slowest value] or less for this test

    Normal value

    A normal value is a single value that occurs most often in a data set.


    Outliers are atypical, infrequent observations: data points which do not appear to follow the distribution of the rest of the sample. These may represent consistent but rare traits, or be the result of measurement errors or other anomalies which should not be modeled. From a purely statistical point of view, any measurement that falls outside of three standard deviations, or 99 percent of all collected measurements is considered an outlier. The problem with this definition is that it assumes that the collected measurements are both statistically significant and distributed normally, which is not at all automatic when evaluating performance test data.

    User Abandonment

    This metric represents the length of time that users will wait for a page to load before growing dissatisfied and exiting the site. Sessions that are abandoned are quite normal on the Internet and consequently will have an impact on the load test results. User abandonment refers to situations where customers exit the Web site before completing a task, because of performance slowness. People have different rates of tolerance for performance, depending on their psychological profile and the type of page they request. Failing to account for user abandonment will cause loads that are highly unrealistic and improbable. Load tests should simulate user abandonment as realistically as possible or they may cause types of load that will never occur in real life — and create bottlenecks that might never happen with real users. Load tests should report the number of users that might abandon the Website due to poor performance. User abandonment can be simulated using duration assertions in JMeter along with “Action to be taken after a Sampler error” set to “Start Next Thread Loop” in Thread Groups.

    Performance requirements

    Performance requirements are those criteria that are absolutely non-negotiable due to contractual obligations, service level agreements (SLAs), or fixed business needs. Any performance criterion that will not unquestionably lead to a decision to delay a release until the criterion passes is not absolutely required ― and therefore, not a requirement.

    Performance goals

    Performance goals are the criteria that your team wants to meet before product release, although these criteria may be negotiable under certain circumstances. For example, if a response time goal of three seconds is set for a particular transaction but the actual response time is 3.3 seconds, it is likely that the stakeholders will choose to release the application and defer performance tuning of that transaction for a future release.

    Performance targets

    Performance targets are the desired values for the metrics identified for your project under a particular set of conditions, usually specified in terms of response time, throughput, and resource-utilization levels. Resource-utilization levels include the amount of processor capacity, memory, disk input/output (I/O), and network I/O that your application consumes. Performance targets typically equate to project goals.

    Performance objectives

    Performance objectives are usually specified in terms of response times, throughput (transactions per second), and resource-utilization levels and typically focus on metrics that can be directly related to user satisfaction.

    Performance testing objectives

    Performance-testing objectives refer to data collected through the process of performance testing that is anticipated to have value in determining or improving the quality of the product. However, these objectives are not necessarily quantitative or directly related to a performance requirement, goal, or stated quality of service (QoS) specification

    Performance Budgets

    Performance budgets (sometimes known as performance allocations) are constraints placed on developers regarding allowable resource consumption for their component.

    Resource utilization

    Resource utilization is the cost of the project in terms of system resources. The primary resources are a processor, memory, disk I/O, and network I/O.


    Setup is the process planned to run before executing any of test scenarios. In JMeter. Setup Thread Groups are used for incorporating processes to execute before any of the normal thread groups starting their tests.


    Teardown is the process planned to run after executing all the test scenarios. In JMeter, Teardown Thread Groups are used for incorporating processes to execute after all the thread groups finish their tests.


    For optimization, motivation refers to the user’s desire for your product or service. It\'s considered by website optimization experts, such as MarketingSherpa, as most important factor in determining a high conversion rate.

    Mobile Optimization

    Mobile optimization means designing and formatting your website so that it’s easy to read and navigate from a mobile device. This can be done by either creating a separate mobile website or incorporating responsive design in initial site layout.

    Conversion Path

    The conversion path is the step-by-step series of clicks that a visitor goes through on your website, from their first interaction with you to whatever goal you’re trying to accomplish on your site.

    Anxiety Elements

    From an optimization perspective, anxiety elements are parts of a web page that create anxiety for your visitors and reduce their inclination to convert on your page.

    Double Opt-in

    A double opt-in occurs when a user signs up for an email marketing list, and then an email is sent out to the user which includes a link to click and confirm the subscription. Only after the confirmation click is completed the user will officially be added to the email marketing list. By using a double opt-in confirmation method, the chance of spam addresses in the deployment list will be greatly reduced.

    Post Back

    In the context of web development, a postback is an HTTP POST to the same page that the form is on. In other words, the contents of the form are POSTed back to the same URL as the form.Postbacks are commonly seen in edit forms, where the user introduces information in a form and hits \"save\" or \"submit\", causing a postback. The server then refreshes the same page using the information it has just received.

    Tracking Pixel

    A tracking pixel is an HTML code snippet which is loaded when a user visits a website or opens an email. It is useful for tracking user behavior and conversions.With a tracking pixel, advertisers can acquire data for online marketing, web analysis or email marketing

    Single Opt-in

    Single opt-in (SOI) is a subscription process where a new email address is added to your mailing list without requiring the owner of that email address to confirm definitively that they knowingly and willingly opted in.

    Case Attribute

    Case attributes are characteristics of a business case and describe it in more detail. Each case has one or more attributes, whereby the attribute values can vary from case to case. Examples of case attributes are specific IT systems or persons responsible.

    Conformance Checking

    Conformance Checking is a technique used to compare event logs or the resulting process with the existing reference model (target model) of the same process. This technique is used to determine whether the target process corresponds to the actual process. Conformance Checking is a Process Mining method used to check compliance.

    Cycle Time

    The cycle time is the time required to complete a process, process variant, business case, or activity. The cycle time is made up of the processing time, the idle time, the transport time, and the waiting time. You can use the cycle time to analyze the process to determine process performance for instance.

    Data Extraction

    Data extraction describes the extraction of data from a system. In the context of Process Mining, this means that event data is extracted from an IT system in order to then perform a data transformation and use this data for analyses.


    “ETL” – Extract, Transform, Load – describes a process in which data is extracted from one system, transformed and loaded into another system. In the context of Process Mining, data is first extracted, then transformed, and then loaded into a Process Mining tool.

    Event Log

    Events are listed together with their attributes in an event log. Attributes that are typically listed are the case ID, the timestamps of the start and end times, and other attributes of the event recorded by the IT system. An event log thus represents one or more cases of a business process. An event log can also be the documentation of several related business processes.

    Idle Time

    The idle time refers to the time between the end of one process activity and the start of the next. During the idle time, a work item, for example a workpiece or document, is not processed, inspected, transported or stored due to a sequence or malfunction. For example, idle times are the time between two production steps or the further processing of a customer ticket. Idle times extend the process and have a negative effect on the cycle time.

    Key Figure

    A key figure represents a measured value or status that is compared with other key figures or used for analyses, for example to monitor performance or identify optimization potential. In the field of Process Mining, frequently used key figures include cycle time and number as well as process costs.

    Lean Management

    The term Lean Management describes the achievement of lean structures and processes in the entire value chain. Accordingly, one of the main goals is the optimization of processes. The aim is to uncover and remedy optimization potentials such as bottlenecks or process loops.

    Optimization Potential

    The optimization potentials in a process are sections or activities whose change can improve the process performance. Optimization potentials are therefore possibilities for improvement within a process. For example, these can be bottlenecks, process loops or inefficient process flows. The optimization potential is realized by eliminating the identified weak points. This can help the process to achieve greater effectiveness, efficiency or conformity. Optimization potentials are often recognized in the course of an analysis of the processes.

    Process Loop

    A loop describes the return to a previous activity or step in a process. The process path is therefore repeated to a certain extent. A loop often follows a decision, for example, as a result of controls.In the case of controls, loops mean that reworking is necessary.

    Process Execution

    The process execution describes the realization of the implemented target processes, now actual processes, in everyday business life. When processes are executed, data is generated that is important for process control with the help of Process Mining. This is part of the process management lifecycle and takes place after process implementation.

    Process Path

    A process path is a specific sequence of events and activities within a process. For example, a process can have several paths that change the process cycle due to decisions and parallelism. If the decision from which the path starts is linked to certain conditions, the outbound paths can have different path probabilities. Each path forms a process variant.

    Reference Process

    A reference process is a process that represents a desired ideal state. The process therefore represents how the process should run. However, this “target sequence” can deviate from the actual process. In Process Mining, the actual process is therefore often compared with the reference process

    Root Cause Analysis

    The root cause analysis aims at finding process errors and their causes. In addition, the identified root cause structure is analyzed. These analyses make it possible to determine the proportion of errors found that have the same cause, for example. Process problems can be caused by impact factors such as bottlenecks. In Process Mining, the cause analysis can be automated and thus time can be saved.

    Waiting Time

    The wait time is the period of time in which a work item, for example a workpiece or document, is waiting for further processing. Waiting may be caused by a person or machine required for the process, even though this person or machine is working at full capacity. Furthermore, wait time can occur if the continuation of the process requires the completion of a parallel work step.

    Work 4.0

    It mainly refers to the consequences of digitization and automation on working conditions and forms. It is assumed that the previous conditions will continue to digitize and change in terms of time, processes and availability of workplaces.

    Test Objective

    Test objectives are the measurement that you use to compare test results. for example, the trailing value of visits or the conversion rates of specific goals.

    Tailing Value / Visit

    The total Engagement value for the variant of the content that is being content tested and that is based only on the page views that occur after the contacts have been exposed to the test. Divided by the number of visits to the site with the variant.

    Cookie Churn

    Cookie churn or cookie churn rate is the rate at which cookies are deleted from user\'s browser over a period of time, usually weeks or months. Cookie churn is important in experiments where the users cannot be uniquely identified across browsers and devices and the only way to persist an experiment treatment across sessions is to rely on a cookie identifier.

    Casual Interference

    Causal inference is a process by which a causal connection is established based on evidence.Causal inference of the frequentist kind shifts the burden of proof on the person arguing for the null hypothesis to the extent to which the data contradicts it, thus data takes central position in the decision-making process

    Error Spending Function

    An error-spending function is a function that governs the cumulative type I or type II error that is \"spent\" at each analysis time during a sequential testing online experiment. A function that governs the rate at which the type I error (alpha) is spent is called and Alpha-Spending while one which controls the rate at which the type II error (beta) is spent is called Beta-Spending.

    Error Probability

    In statistics, an error probability is the frequency with which a certain probabilistic testing procedure will lead to a type I error or a type II error. In other words, it is the rate of occurrence of an error in a hypothetical infinite repetition of the procedure.

    Effect Size

    Effect size is the magnitude of the difference between a hypothesized and an observed value of a parameter. The parameter is usually an unknown variable theta (θ) and can be either a primary KPI or secondary KPI.

    Factorial Design

    A factorial design is a type of online controlled experiment in which the outcome of interest is the contribution of individual factors to a variable of interest (often a KPI) and not higher-order interactions between these factors.

    Futility Boundary

    A futility boundary is a statistical decision boundary used in sequential testing such as an AGILE A/B test. It is built in such a way that it maintains the type II error probability larger than a specified level, on average. It is usually computed using a beta spending function. Crossing the boundary means that the probability of detecting a statistically significant outcome has fallen below the desired.

    Frequentist Inference

    Frequentist inference is a collection of error probabilistic methods which allows us to learn from data about the true state of nature in the presence of uncertainty by using model-based inference. It\'s core goal involves providing error control in the face of uncertainty.