Canonical tag is a feature used to prevent duplicate URL formation.
Google may see the URL addresses of pages that can be accessed with more than one URL as duplicate content, or the URL addresses of pages with similar content may also be viewed as duplicate content by Google.
If it is not specified which page is the canonical page, Google will determine one of the URLs with similar content as the canonical page and see the other pages as duplicate pages and crawl these pages less or give equal importance to both, this is entirely dependent on Google’s algorithm. will vary accordingly.
To avoid this situation, the canonical tag should be used in the source code of the pages.
Canonical URL is the canonical page which is the main one among the pages that are close to each other or repeating each other.
Google shows the canonicalized (specified as the standard page) page in the search results pages. For example, if the same page has a separate URL version for mobile and desktop or even amp page, whichever page from these three pages is canonical will be shown on the search results page.
The canonical page is specified by adding a tag to the source code of the web pages in the code structure below.
<link rel="canonical" href="https://juniortoexpert.com/en/what-is-canonical-url/" />
Adding the canonical tag to the source code indicates the canonical page, but Google can choose another canonical URL for any reason.