A cookie is a piece of information sent to a browser by a Web server (website) and then returned by that browser back to the Web server. Its purpose is to "remember" a user’s previous visits. For example, on a retail site, cookies detection might be used to remember which items a user has placed in her shopping cart, which types of items she’s purchased in the past or simply just to remember her login name. While having cookies detection activated on your site in and of itself is not a bad thing, making them mandatory should be avoided, as search engine spiders are unable to accept cookies and consequently will not be able to index content from your site.
