What is Canonical URL – SEO Term

It is the URL of the page that Google thinks is most representative of a set of duplicate pages on your site. For example, if you have URLs for the same page

https://example.com/black-shoes/black-and-red-shoes/
https://example.com/red-shoes/black-and-red-shoes/

Google chooses one.

How to detect a canonical URL

This type of URL can be seen in the source of a webpage, by searching for rel="canonical". It is an element only the search engines see, your users won’t be affected by it.