Four categories of turbine engines

Basically aircraft turbine engines consist of the following components: a front-end air inlet, a compressor, a combustion chamber (combustor), the turbine itself, and often, a propelling nozzle. There is also the turbine starting unit responsible for starting the engine, which draws power from a battery or a portable power source. Aircraft turbine engines themselves fall into four main categories:

Turbojets

The concord is the most famous example of a turbojet engine. They are extremely powerful and as a result, with the exception of the concord can only be found on missiles. This type of turbine relies exclusively on exhaust expelled for propulsion. One drawback is that they are only efficient at high speeds.

Turbofans
Turbofans are the type of engine that you will find on the average passenger aircraft. Just like the turbo jet above, the fans sends air into the combustor and uses the exhaust for propulsion. However, there is also a second stream of air that is sent through the outside for more thrust.

Turboprops

Unlike the above two, turboprops use the gas turbine to provide power to rotate a propeller. The propeller itself provides all the thrust. There is no thrust generated from the exhaust of the turbine.

Turboshaft

Much like the above, the energy is used to drive a shaft rather than to produce thrust using the jet exhaust. Unlike the turboprop, in most cases the shaft is used to drive other devices such rotors on a helicopter.