The jet engines have proven to be superior to all other engines in all respects and have attracted the attention of a number of experts from different areas. They are one of the most demanding systems on the aircraft itself and are used for its propulsion. This paper briefly describes the historical development of jet engines, which were first used in 1939. The development of its basic components - compressors, combustion chambers, turbines and nozzles, injectors and fans - enabled its overall development and better performance. There were also different types of jet engines as a result of the search for a more favorable and efficient air intake and engine operation. The paper also describes the basic physical laws of the jet engine, the way of measuring its power and the principle of work. Particular attention is paid to the Brayton cycle as the basis for all gas turbine and jet engines. The ideal and real Brayton cycle and its processes are described. The materials used in the manufacture of jet engines are also described and the method of controlling the quality of jet engines.