If a single web page can be accessed via multiple distinct URLs, the canonical URL is designated as the “preferred” version for search engines. Defining a canonical URL is essential for preventing the indexation of duplicate pages.
It is standard practice for pages to be accessible through several different URLs. For instance, users might access a website by entering either “[suspicious link removed]” or just “yourdomain.com”.
By formally designating a canonical URL, you communicate to search engines which of these addresses they should recognize as the master primary version. This ensures that they focus their crawling efforts solely on that URL, thereby preventing the same page from being indexed multiple times under different addresses.
If no canonical URL is explicitly set, search engines will typically determine one automatically. When search crawlers encounter multiple instances of identical content, they attempt to identify the version that appears to offer the most complete and robust information set, and then assign that version as the canonical choice.