Propeller engines are a type of aircraft engine that use a rotating blade, or propeller, to generate thrust. The engine converts fuel into mechanical energy, which turns the propeller. This movement pushes air backward, propelling the aircraft forward. Propeller engines are commonly found in smaller planes and some military aircraft, offering efficient performance at lower speeds. These engines can be either piston engines or turboprop engines. Piston engines work similarly to car engines, while turboprop engines combine a gas turbine with a propeller. Both types are known for their reliability and are often used in regional flights and training aircraft, making them essential in aviation history.