What's the difference? I'm not sure there's much you can do with multiplayer?

None unless u wanna trade or do rotations

But once u get ur build online u can do everything alone

What do you mean rotations, sorry i'm new to D4

Also, can i do PVM with people online? is better than single player? not sure how this game works? Plz give me the rundown!!

It has a feature called enlisted parties and it feels like what i believe Craiglist is.

I think party xp bonus is solid. And probably dark citadel you can't do solo.