Canonical links tell search engines which URL is the preferred version of a page when the same content is available through multiple web addresses.
Without a canonical link, search engines may split ranking signals across duplicate URLs, or worse, index the wrong version of a page. Setting a clear canonical avoids this and consolidates your SEO value onto a single URL.
In most cases the platform manages canonical links automatically. This becomes relevant when you are troubleshooting duplicate content showing in search results.