Have a question, what is the SEO Recommended in Magento 2.2.5 canonical category of products?
The rel=canonical element, often called the “canonical link”, is an HTML element that helps webmasters prevent duplicate content issues. It does this by specifying the “canonical URL”, the “preferred” version of a web page – the original source, even. Using it well improves a site’s SEO.
*The idea is simple: if you have several similar versions of the same content, you pick one “canonical” version and point the search engines at it. This solves the duplicate content problem where search engines don’t know which version of the content to show in their results. *
I referred from below links...
Magento 2 - How to enable the canonical meta tag ?
Naigate to Stores -> Configuration -> Catalog -> Catalog -> Expand Search Engine Optimization section
Enable or Disable Canaonical link for categories & products
Use Canonical Link Meta Tag For Categories -> Yes/No
Use Canonical Link Meta Tag For Products -> Yes/No