Why are peertube channels federated like a magazine or a community on lemmy?

I've been using #Kbin for a while since reddit exodus, but it wasn't until like a week ago that I decided to create an account. It's been great, it is the best way for me to experience the #fediverse, I used mastodon and firefish before, but I think I like more the community format, and not losing the possibility to follow...