Am I missing something with Pipelines?

I haven’t been using builds or pipelines with my gitlab install. I noticed today that several of my projects have a “Commit:skipped” icon next to the project name. Curious I checked a couple of projects and headed over to the pipelines tab. A lot of projects have many pipelines, all labeled skipped and all “by API” (but associated to a users commit)

Maybe I don’t understand what pipelines are for. When reading the documentation they say pipelines are a group of builds. I don’t have any builds, so where are these pipelines coming from?

They don’t seem to be having an effect on how I’m using gitlab but it is rather an annoyance I can’t figure out what they actually are for / do / are coming from.

Any help clearing this up would be welcome!
Thanks,