Canonical URL
Definition
A canonical URL is the preferred version of a page's address, declared via a link tag, that tells search engines which URL to index when duplicates exist.
Plain English
It answers "which URL is the real one?" when a page is reachable at multiple addresses.
Why it matters
- Prevents duplicate content issues across URL variants.
- Consolidates ranking and citation signals to one URL.
- A broken or missing canonical can split visibility.