Why are apps randomly appearing in dock?

Hi, just got an iPad and it’s been awhile since I last used iOS, so I’m still learning. One thing I can’t seem to figure out is why apps keep appearing in my dock. The attached picture shows what I mean. If I had to guess, maybe it’s making suggestions based on what time of day i use the app? Regardless though, I find it annoying and can’t figure out how to disable it. I’ve gone through settings and unchecked everything I would think might cause this. Is there something I’m missing? Thank you for any help with the admittedly trivial issue!