How do turbines work?

A simple turbine.

Air is drawn into the engine continuously and compressed by a series of rotating blades. Fuel is sprayed into the combustion chamber and burnt increasing the gas temperature to around 1200C.

The hot high pressure gas expands through a second set of blades mounted on the same shaft as the compressor blades. The energy of the gas is partially expended powering the compressor, but has a residual energy which is either expended as a hot jet (resulting in thrust) or which drives a further independent set of blades to power a propeller or other device.

see http://www.rolls-royce.com/education/schools/how_things_work/journey02/index.html