A turbojet engine is a type of jet engine that generates thrust by expelling high-speed exhaust gases. It works by drawing in air, compressing it, mixing it with fuel, and igniting the mixture. The resulting hot gases expand and are expelled through a nozzle, creating forward thrust. Turbojet engines are commonly used in military aircraft and some commercial jets. These engines are known for their simplicity and high-speed performance. However, they are less fuel-efficient at lower speeds compared to other engine types, such as turbofan engines. Despite this, turbojets remain important in aviation history and technology.