Nofollow

Nofollow is a value you can add to a link's rel attribute. It signals that the site owner doesn't want to endorse the destination. It was introduced to fight comment spam and is now used for paid links, user content and anything the publisher can't vouch for.

Since 2019 Google has said it treats nofollow as a hint, not a command, so it may still use such links in some cases. Even so, you shouldn't plan on nofollow links moving rankings. They can still send real visitors and make your brand visible, which has value of its own.

Practical point: a natural profile has some nofollow links in it. Wikipedia, many forums and large publishers use them by default. Don't chase only dofollow, and don't be alarmed if a good editorial site applies nofollow. Judge the placement on audience and relevance first.