Alternative product module is the new way of adding any product, except related, up selling, and cross selling products. It enables you offer alternatives to the current product, which is more engaging and relevant to the owner of the store.
On the product page, left side a different block is provided for an alternative product, so that the owner can add whichever product in that block.
Magento Editions Compatibility:
Community Edition: 1.7.x, 1.8.x, 1.9.x