Canonical URL Meaning in Plain English
The preference is commonly declared with a canonical link element in the HTML head. Search engines treat it as a signal and may select another canonical when other evidence conflicts.
A canonical does not send visitors elsewhere. A redirect does. Use the mechanism that matches the actual need.
Example
<link rel="canonical" href="https://example.com/main-page">Tracking parameters may create several URLs that display the same content. A canonical can point those variants toward the clean primary address.
Why It Matters
Consistent canonicals help consolidate duplicate URL signals and make the intended indexable version clearer.