A helicopter is a type of aircraft that is lifted by one or more rotors on its top. Helicopters have another small rotor on their tail for balance and steering. Normal airplanes get their lift from air flowing over their wings. Because helicopters get their lift from the rotating blades on their top, they don't need a runway to take off, and can just go straight up from a standing start. They can also turn around on the spot while they are in the air.