The document summarizes how gas turbine engines work. It describes that gas turbine engines have three main parts: a compressor that pressurizes incoming air, a combustion area that burns fuel to produce hot gas, and a turbine that extracts energy from the gas to power the compressor and provide output. The document outlines the basic process of how air is compressed, fuel is burned to heat the air, and the hot gas spins the turbine before exiting. It also provides examples of different types of gas turbine engines and their applications in aircraft, power plants, and tanks.