Why is a jet engine called an air breathing engine?

A jet engine is called an air-breathing engine because it draws in ambient air from the atmosphere to mix with fuel for combustion, rather than relying solely on an onboard oxidizer like a rocket engine. The engine compresses the incoming air, mixes it with fuel, ignites the mixture, and expels the hot gases to produce thrust. This process allows jet engines to operate efficiently at high speeds and altitudes. The term emphasizes the engine's reliance on atmospheric oxygen to function.