A Jet engine is basically a gas turbine engine that uses compressed and heated air for greater propulsion. A jet engine has 4 main sections, the compressor, combustion chamber, turbine and the exhaust. Concepts for a gas turbine engine dates back in 1791, however, practical use for such a device is limited by the avialable metal alloys at that time. The first practical jet engine came into existence in the 1930s. A patent by Frank Whittle of the RAF in 1932 allowed further developments on the engine. However, a similar design in Germany by Hans von Ohain in 1935 was the one that ultimately lead to the the Heinkel He 178, the first turbojet powered aircraft.
Jet powered aircrafts came in a little too late during World War II, the need for fast attack fighters cannot be made possible by existing piston engines at that time. The development of jet engines quickly replaced piston powered fighter planes after the WW2. The first jet aircraft designed specifically for hauling passengers is the de Havilland comet in 1949 by Great Britain.
Major jet engine manufacturers
Rolls-Royce plc. (LSE: RR
General electric (NYSE: GE
Pratt and whitney - United Technologies (NYSE: UTX