The default link behaviour: a regular
<a href> with no rel attribute, which passes ranking signal (historically called "PageRank") to the target. The term only exists as a counterpart to nofollow, sponsored, and ugc — there's no actual rel="dofollow" attribute, and adding one does nothing. In SEO conversations "a dofollow link" means an editorial link from a real site that hasn't been marked as paid or untrusted. Since 2019 Google treats nofollow, sponsored, and ugc as hints rather than strict directives, narrowing the gap somewhat.