Explain coop?

[Neckstabba]

How does coop work? Can i just match with anyone ? Is there a level limit - level range i need to be into to get matched?

I actually liked the Dark Souls type of Summons more. They were more specific WHERE you get spawned.

If i join people, i get into areas that i didnt even reach. Im not really sure how "far" i can get dragged? I wish the explaination would be better..

[Charnel]

Only the host world progresses like all fromsoft games
You can match with anyone if you choose that option or anyone can join you if you allow it
It will generally put you in the similar area you are
The coop partner will get scaled to the host more or less (including invaders)