Aerobatics are tricks a pilot does on purpose in a plane: loops, rolls, flying upside down, diving and then pulling up again. It is like circus acrobatics, but with a machine in the air. You see it at air shows, and some pilots train for competitions. Though actually, this is not ordinary flying. A passenger plane tries very hard not to do any of it — those sudden turns would scare people and stress the aircraft. The word feels a bit technical, but news and show programmes use it; in loose talk people may just say stunt flying. It names the activity (she does aerobatics), not a single move.