This document provides an overview of jet engine basics. It describes the main types of jet engines as piston engines, gas turbine engines, and turbojet engines. The key parts of a gas turbine jet engine are then explained, including the compressor, combustor, turbine, and types of shafts. The different gas turbine engine types - turbojet, turboprop, turbofan, and turboshaft - are also defined along with their typical applications.