What is "rel="?
- In HTML "rel" defines the relationship between the document using it and the linked document / resource.
- rel stands for "relationship".
- The rel attribute typically explains why (or in what manner) you are linking to something else.
rel=amphtml
rel=amphtml is used within a HTML file that also has AMP version. It basically states that there is an AMP version of this document available.
rel=apple-touch-icon
rel=apple-touch-icon provides an image that represents the current page for use on Apple devices (like a favicon, but for Apple).
rel=author
rel=author indicates that the referenced document provides further information about the author. It basically states that the linked document is about the author of the page or article.
rel=canonical
Using rel=canonical defines a preferred url for search engines which can help with ranking and duplicate content issues
rel=dns-prefetch
rel=dns-prefetch allows you to pre-resolve DNS for specific domain names to achieve faster pageloads in many situations.
rel=nofollow
rel=nofollow It indicates that a link is not endorsed by the original author or publisher of the page or that the link is of commercial / paid nature.