Cintematic/Dynamic camera mode
Well, if you've played Star Wars: Empire at War, you'll know exactly what this is. If not, let me explain.
It's a camera mode which pans around the battlefield, often zooming in and catching glimpses of action. If not in a battle, it would follow your units. It shows from various places and angles, based on where your troops are. It's more for when you want to sit back and take screenshots rather than play, really.