NoFollow
NoFollow is a value that can be assigned to a rel attribute in an HTML link to indicate to search engines not to follow the link in their ranking algorithms. It is the inverse of the follow attribute.
This can be useful for handling links to resources that we do not wish to fully endorse or over which we have no control, especially to untrusted or irrelevant websites-while for links that are published for a fee or sponsorship or that are user-generated, two other attributes, “sponsored” and “UGC,” respectively, have been introduced.
The nofollow link had directive value for Google, which then compulsorily ignored the link in SEO terms; since 2020, however, Google has changed nofollow to a suggestion for crawlers and, therefore, there is a possibility that Google will choose to ignore the suggestion of the nofollow attribute and use that link for ranking purposes as well, in addition to classic crawling purposes.