Let's talk about a canonical URL. This is a webpage's address that's considered a priority among a group of duplicate pages. A canonical URL is the one that's added to the index by a search engine. You’ll use a canonical tag on a page when the same content is available at a different URL but in a different version.You'll find the canonical URL in the section of a page as an HTML tag. It's how Google knows which webpage has original content. This way, your search engine knows what to crawl and to ignore the duplicates.