A kind of jet is a type of aircraft that uses jet propulsion to fly. GAS, PROP, Lear, RAM, and turbo are all types of jets. A GAS jet is powered by a GAS turbine engine, a PROP jet is powered by a propeller, a Lear jet is a type of business jet, a RAM jet is a type of jet engine that uses the forward motion of the aircraft to compress incoming air, and a turbo jet is a type of jet engine that uses a turbine to compress incoming air.