Practical explanation:
Websites can generate different URLs that lead to the same content, for example through filters, tracking parameters, or category paths. Without guidance, search engines may treat these pages as duplicates. A canonical URL clearly tells search engines which version should be considered the primary one.
How it’s used in practice:
A canonical URL is set using a canonical tag in the page’s HTML. This helps consolidate ranking signals into one URL and avoids splitting visibility across multiple similar pages.
When to use it:
Canonical URLs should be used whenever the same content is accessible through more than one URL and only one version should appear in search results.
Related terms:
Duplicate Content, Technical SEO, On-page SEO