Yes. That’s expected.
Unicorn is the thing serving pages. Ruby is the language discourse is written in. You can see that unicorn launcher started all of those processes.
If you look at what’s running on your windows or Mac computer you don’t know what all of those things are either. 
I’m really not sure how you’d go about learning that. Maybe the rails documentation? For a new system administrator there are lots of other things that are more likely to be useful.