What do airplanes do?
Airplanes fly under their own power which means they can have a sustained flight until they deplete their power source - as opposed to gliders that maintain flight by an initial exterior power source and airships that fly by being buoyant in the air, or floating like a ship on water. also planes fly by producing lift on wings or a lift producing body (a lifting body) - as opposed to a missile that flies entirely by its power source being greater than gravity, friction and other forces acting against the flight or by being "pushed" by external forces like a glider to overcome the same forces. Helicopters are airplanes as the rotor is a spinning wing so they fly under their own power and produce lift - if you have ever seen one of the small aerobatic aircraft that can "hover" in vertical position it is still acting as an airplane since the prop is now acting as a spinning wing - but one of the new fighter jets doing the same thing would then become a powered missile rather than an airplane since it is no longer producing any lift. The term aircraft can refer to any of these types that operate in an air environment: airplane, glider, airship or missile.