A jet engine is a type of reaction engine discharging a fast-moving jet that generates thrust by jet propulsion. While this broad definition can include rocket, water jet, the term jet engine typically refers to an airbreathing jet engine. In general, jet engines are combustion engines.
Airbreathing jet engines typically feature a rotating air compressor powered by a turbine, with the leftover power providing thrust through the propelling nozzle. The aircraft use such engines for long-distance travel. Most modern subsonic jet aircraft use a more complex high-bypass turbofan engine. They give higher speed and greater fuel efficiency than piston and propeller aeroengines over long distances. A few air-breathing engines made for high-speed applications (ramjets and scramjets) use the ram effect of the vehicle’s speed instead of a mechanical compressor. And then there are so many different types of engines, which each have their own thrust rating. Roughly speaking, an engine can cost anything from 12 to 35 million dollars.
The Jet Engine Alliance GP7000 is a turbofan jet engine manufactured by Engine Alliance, a joint venture between General Electric and Pratt & Whitney. It is one of the powerplant options available for the Airbus A380, along with the Rolls-Royce Trent 900.