For interaction designers, affordances are absolutely essential - otherwise users just wouldn't know what they can and cannot interact with.
The title is about affordances but the article is mostly about signifiers. It is lists the types of signifiers and breaks each type down.
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Or there's this article: https://www.webdesignerdepot.com/2015/04/6-types-of-digital-affordance-that-impact-your-ux/ but she calls them affordances where Jerry Cao calls them signifiers.