Meaning and importance of rel attribute of a tag for SEO

About rel tags

nofollow

By setting nofollow to the rel attribute of the a tag, you tell search engines not to follow the link.
Normal links pass link juice (page rating) to the linking page, but links with the nofollow attribute do not pass any rating.

https://searchengineland.com/infographic-nofollow-tag-172157

It is recommended to add nofollow for user-editable data, ads, etc.

noreferrer

By adding noreferrer to the rel attribute of the a tag, you can prevent referrers from passing referrer link information.
By not passing the referrer link information, it will be safe even if the URL link contains information you don't want to pass.

noreopener

If the a tag keeps target="_blank", add noopener to the rel attribute.
By adding noopener, you can open a new tab in a separate thread.

The main reason to add this is security.
If you don't add noopener, JavaScript will be able to manipulate the window.opener object, and the page opened in the new tab will be able to manipulate the page in the original tab.

Importance of rel in HTML Coding

It is important to understand the meaning of the rel attribute above and implement it correctly.
This will help you secure your site and convey the correct value of your site to Google Search Engine.