Aircraft operates because of the engine which gives the aircraft the power to go forward. It is the engine and the wing due to which aircrafts and rockets fly.
But engines are not the only contributors in the flight of an airplane. After all, the gliders and birds don’t need engines to fly, mainly because they have wings.
So engines and wings have different roles to play towards the flight of an airplane. The engine of an airplane helps it move forward, which throws the air over the wings and in downward direction, which provides an up thrust to the plane. This up thrust is called lift which keeps holding the plane in the sky. So the engine moves the plane forward while wings help it move upward.
So the airplane flies because the engine gives the thrust and wings give the lift.
Rockets, however, use rocket engines to boost them upwards and they fly straight.