Canonicalization
Canonicalization tells search engines which version of a page is the main one when multiple URLs show the same content. This Implementation practice prevents duplicate content issues that can split your Link Equity and confuse Ranking Factors across different URL versions.
You add canonical tags in your Meta Tags by putting a link rel="canonical" tag in the page head that points to the preferred URL. Common cases include handling www versus non-www versions, HTTPS versus HTTP, and pages with tracking parameters. Your URL Structure affects this too, since different paths or parameters can create duplicate pages that need canonical tags.
The canonical tag guides search engines to index the right version and pass all ranking signals to it. This helps your Site Structure stay clean by preventing wasted crawl budget on duplicate URLs. Make sure your Sitemap only lists canonical URLs, and use Redirect Management for permanent URL changes rather than relying on canonical tags for redirects.