rel-canonical is a way for specifying preferred URLs using link elements in HTML pages within the HEAD tag. It can help in situations where more than one page has duplicate content. {link rel="canonical" href="http://example.com"}
rel-canonical is a way for specifying preferred URLs using link elements in HTML pages. An example of such an element would be:
<link rel="canonical" href="https://example.com/preferred-url" />
It should be used in the <head> section of the webpage.
Canonical URLs can mitigate against ill effects of duplicate content. When two URLs have the same page, rel-canonical links can let search engines know which one should be indexed.
rel-canonical is just one implementation of canonical-urls. The other way to implement canonical URLs is with 301-redirects.
