A standard tag (otherwise known as "rel sanctioned") is a method for telling web crawlers that a particular URL speaks to the ace duplicate of a page. Utilizing the standard tag avoids issues caused by indistinguishable or "copy" content showing up on different URLs.
Canonical Tags helps search engine to understand the actual url of the website, it helps to indexed our correct version of web pages on search engine....
The canonical tag is a new tag proposed by Google, designed to minimize crawl errors and the indexing of duplicate content in your website. Support for the tag has been adopted by most of the search engines, and it’s a good idea to add to your own website if you want to get your best search engine rankings.
The canonical tag is an essential tool in the search engine optimization toolbox. It is often a better solution that a 301 redirect in cleaning up duplicate content issues. A canonical link element is an HTML element that represent (rel="canonical").