Nofollow
Nofollow is a link attribute telling search engines not to pass ranking credit through that particular link. It suits paid placements, user-generated content and untrusted sources. Since 2019 Google has treated it as a hint rather than a strict instruction.
Why it matters for your rankings
Nofollow was introduced to fight comment spam and became the standard way of declaring a link you do not editorially endorse. Google now also offers rel="sponsored" for paid links and rel="ugc" for user-generated ones.
Two practical points get missed. First, nofollowed links still carry real value: referral traffic, brand exposure and the discovery that leads to genuine editorial links later. Judging a placement solely on its rel attribute discards most of its worth. Second, using nofollow to sculpt internal PageRank does not work and has not for years. On your own site, if a page is not worth linking to, do not link to it rather than nofollowing the link.
How to check it on your site
Check what your links actually carry
Inspect the HTML rather than trusting a plugin's settings. Themes and plugins frequently apply attributes unexpectedly.
Mark paid links correctly
Any sponsored, affiliate or paid placement on your site should carry rel="sponsored" to avoid being read as a sold link.
Do not nofollow your own pages
Internal nofollow is not a crawl control mechanism. Use noindex or robots.txt where exclusion is genuinely needed.
Value placements by traffic too
Check referral sessions in GA4. A nofollowed link driving real visitors beats a followed one nobody sees.