To compare products, please follow the next steps:
While in the category page, you can click on the "Add to compare" button which is right below the "Add to Cart" button of each product.
After adding a product to the compare list, you will see a confirmation message.
After seeing the confirmation message, if you scroll down in the category page, you will see the product you added to the compare list in a menu on the left of the page.
After adding as many products as you need to compare into the compare list, you can go to it either by clicking on the link given in the confirmation message,
or by clicking on the "Compare" button found in the compare list menu.
To delete products from the Compare list, simply click on the "X" that accompanies each product in the list.