A turbofan is an airbreathing jet engine that is widely used in aircraft propulsion. It consists of a fan, compressor, combustion chamber, and turbine. The fan section of the engine compresses and accelerates the air, which is then mixed with fuel and burned in the combustion chamber. The hot exhaust gases are then passed through a turbine, which extracts energy from them to drive the fan. Turbofans are generally more efficient than turbojets, as they can produce more thrust for less fuel. They are also quieter and produce less emissions than turbojets.