What is a Canonical URL?
Canonical URL tag identifies the source URL or the original content page of a particular page (having multiple URLs) to search engines.
www.example.com
example.com
www.example.com/index.html
example.com/home.asp
http://www.example.com
https://www.example.com
From a search engine perspective all the above URLs are all different URLs. And for the above site the canonical URL Tag looks like is,
<link rel=”canonical” href=”http://www.example.com/Sample+page” />
Usage of Canonical URL:
Search engines don’t like duplicate content at all. So, having similar or identical pages on your website can be a reason for ranking devaluation by the search engines. Therefore, by properly using canonical tags to pages on your site, you can avoid this problem.