Does matrix have a voice/video functionality or is it strictly text chat?

In all of these new-to-me resources, i see a lot of people saying they are self hosting. Do y’all selfhost on like y’all’s main PC or do y’all have a home server stack y’all use?

I’ve been seeing things about matrix more and more and it’s seeming like something interesting. I checked out their website and, like a lot of this stuff, it’s a bit unclear for me.

So you do as you do here and set up an account on an instance and then port everything through it? Does smashing all the different chats into one list have a way to differentiate them from one another? I’m just looking for more about it to help me understand it.