If a website backlinks to another website and allows search engines to follow this link, it is a dofollow link. These links matter to the ranking of a website. The more high-quality dofollow links one has, the higher on the search result they will end up. High-quality dofollow links mean:
- the website that has posted the link is relevant
- the anchor is relevant
- the website that has posted the link produces high-quality content and does not have spam or malware
The opposite of the dofollow links is a nofollow link. Nofollow links can be only followed by users. They may not matter to SEO that much but they still can drive traffic to the website. Up until 2019, Google search crawlers never followed nofollow links but nowadays it is more of a recommendation than a command. Therefore, it makes sense to carefully monitor the quality of nofollow links as well.
