When a website points to another site through a backlink, this link is automatically considered as an inbound link in SEO metrics. This backlink allows the target website to benefit from the SEO juice of the source site to increase its ranking in the Search Engine Results Page (SERP). In that case, we speak of a do-follow link.
It is however possible to specify a “nofollow” tag when you do not want Google to take a link into account or to associate it with your website. The source site will still point to the target site but no SEO juice will be passed down to it.
For example: the tag "<a href="https://www.youdot.io/">Youdot</a>" will become a link like Youdot while the tag "<a href="https://www.youdot.io/" rel="nofollow">Youdot</a>" will generate a no-follow link.