A turbojet 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, propelling the aircraft forward. Turbojets are known for their simplicity and high-speed performance. These engines were widely used in early military and commercial aircraft, such as the Boeing 707 and McDonnell Douglas F-4 Phantom II. However, they are less common today, as more efficient engines like turbofans have become the standard for modern aviation.