What is the usage of canonical tag? I am selling products through my website. In my pages apart from the product name the other contents are similar. Do I need to use canonical tag!
If content on different pages are similar then it can be case of duplicate content and should be avoided.
canonical tag is meant for redirection from non www version to www version..and as far as concern about same content this will take issue as duplicate content..
I do not think canonical tag is the solution for you, although I am saying that without seeing the site. Canonical tag is meant to help avoiding duplicated content, which means same page in different urls - that usualy happens when a new parameter is added to the page and can be indexed as well. I suggest you read more here: googlewebmastercentral.blogspot.com/2009/02/specify-your-canonical.html