An engine is something that produces some form of output from a given input. Military engines included siege engines, large catapults, trebuchets, battering rams, etc., so the first engineers were military engineers. Later came civil engineers, who designed and built roads, bridges, docks and buildings.An engine whose purpose is to produce kinetic energy output from a fuel source is called a prime mover; alternatively, a motor is a device which produces kinetic energy from a preprocessed "fuel" (such as electricity, a flow of hydraulic fluid or compressed air).A car has a starter motor, a windscreen wiper motor, windscreen washer motor, a fuel pump motor and motors to adjust the wing mirrors from within the car and a (motorised) radio antenna - but the power plant that propels the car is an engine. Again an aircraft will have many motors installed for operation of its many auxiliary operations and services, but aircraft are propelled by engines, in this case, jet engines.
Usage of the