crews
Well, like a lot things on this Euro-centric fora, it matters what side of the pond you are on as to the exact terminology.
An augmented crew is usually 3 pilots, and a heavy or double crew is 4 pilots so that you have 2 sets of pilots allowing you to fly over 12 hours pushing you into what many call the ultra long haul realm.
Duty and rest rules vary around the world. I am am a USA based Part 121 pilot.