Airship
An Airship is kind of lighter-than-air aircraft.  It floats in the sky and need not move to stay up.  That is because it is filled with a lifting gas that is more lightweight than air.  This is different from aeroplanes that stay up in the sky by moving. An airship floats like a balloon. But an airship is different from a balloon. An airship has an engine for power and a way to control its direction of movement. A balloon does not have an engine or a way to control its direction of movement.