Moz has a good article (from 2014 and kind of long but really a good resource) here about how Google names different parts of their algorithm (just when you thought those guys couldn’t get any darn cuter, they do and go something like this). It’s been that way for years, but I didn’t realize they named a couple of different parts. And maybe you didn’t, either, so let’s get to reading!
SEO is an ever evolving art, and you can’t just “do” it and forget it. If you run a site, you need to keep educating yourself as things change and improve. Side note – does the panda in the featured image for this post look like he’s judging you, hard? That’s what I thought, too.