What is a Canonical Tag?
Canonical tag rel= "canonical" is the HTML tag for informing search engines about the original page among a group of duplicate pages. It is added to the head <head> element of the webpage.
The webpage to which the canonical tag is added is called the canonical URL. If you review the source code of that webpage, the canonical tag will be declared, as shown below.
<link rel="canonical" href="http://yourdomain.com/yoga-for-beginners/">
The canonical tag is crucial when you have different versions of the same webpage. This way, you can let search engines know which webpage is the original.
If you do not specify a canonical URL, the search engine will decide on one, and it may select an incorrect one.