Here's how it works:
* Engines convert fuel into energy. This can happen through combustion (burning fuel) in piston engines or through turbine engines (where compressed air is used to spin a turbine).
* The energy created is used to move air. In piston engines, a propeller is spun. In turbine engines, air is accelerated out of the back of the engine.
* The moving air creates thrust. As air is moved backwards, the airplane is pushed forward by the equal and opposite reaction (Newton's Third Law).
Let me know if you want to know more about the different types of airplane engines!