Session hosting is when a server, or computer, runs your game’s matches. Each match, with a set group of people, is considered a session. And session hosting is where that match is taking place.
We use this term for running multiplayer games
Think of a match for Call of Duty. You’ll have 150 players in that one instance, with a time limit of 40 to 60 minutes. This is what we would call a session.
There are different ways to host your sessions
For that session to run, you’ll need to host it somewhere, ideally close to the players so they don’t experience lag or bad gameplay. And there are different types of servers you can use to host your game, depending on what you need.