Hi,
the point is: when playing a game you need a camera that gives you a picture. This Camera is attached to a Character in most cases, but you do not need a character. You can create your own Pawn and use it as DefaultPawn in the GameMode. The Pawn can be a character but it does’nt have to be. It can be just a USceneComponent with an attached camera.
Hope it is understandable 
Cheers