[2021] couch vs online?

Yep! If you connect more controllers to your machine you can have multiple players locally playing online. They just need to press A in the Online Lobby to join the party.

Quickplay FFA or 3v3 -- you can queue with a party of up to 3 (so up to 3 local will work here)
Chaos (4v4 or 5v5) -- you can queue with a party of up to 5 (so up to 5 local will work here)

Party Only a.k.a. private match If you have a custom party, you could technically connect 9 additional controllers and play 10 local online (not sure why you would do online though if all players are local haha)
Allows you to mix and match with friends in other places

Let me know if you need further clarification!

Brett

No problem! There's also crossplay if you want to play with friends on consoles. You can get into the same party using the room code system at the top of the Online Lobby :)