What is a canonical URL?
A canonical URL is the address of a page that is defined as the originating page and reported to search engines, so that they do not index other pages that already occupy the original content. It is the canonical, canonical, rel canonical and even canonical meta tag found all over the web. It is a tag inserted in the HTML code that will indicate to search engines that the page is canonical.
A canonical URL is an address that search engines are expected to treat as the originating page
Questions about editorial content are almost universal on the internet. A text, or even a page, is copied and republished quickly or with little conversion on other sites, whether advertising or plagiarism.
This phenomenon is more frequent when the relevant information is interesting. However, search engine algorithms do not like duplicate content and penalize it by denying access to SERPs (Search Results Pages). The concern is that the original page could be confused with one of the duplicate pages by bots like Google bot. To overcome this problem, Google Engine offers a solution allowing webmasters to indicate the original page as canonical as soon as it is created.
Webmasters will use the format <link rel=”canonical” href=”https://www.monsite.com/url-de-la-page.html”> and in the <head> and </head> tags. This will allow it to identify similar pages created after the original page as non-original pages and to consider only the owner during its page indexing operations. This choice has a double advantage: it does justice to the original content and avoids an overload of indexed pages in search engine databases.
Canonical URLs are meant to prevent content theft, not 301 redirects
Obviously, the ideal is to standardize all the pages of your site. On the one hand, this is necessary when you have to create internal duplicate pages, for example, in the case of product sheets, duplicate a page n times so as not to be indexed by Google and no longer rewarding in terms of SEO.
This is also useful when the text on that page can be picked up by other publishers to create its content, especially since some bots are mandated to automatically steal content to serve it to other sites. This will be the canonical page that the engine will display in the search results page for a given query.
It is important to note that this solution shares many similarities with 301 redirects, which cause the engine to choose one page over another. The difference is that canonical URLs are only used by search engines and are used for indexing, while 301 redirects send search engines and users from the old page to the new page, which looks more to an update.
The usefulness of making this distinction is the relevance of technical choices to redirect users or search engines.