A turbine works like a compressor in reverse. Static nozzles convert pressure to velocity, and a moving section converts that velocity to rotational motion. Again, there are two types, both centrifugal and axial, but axial turbines are far more common.
Considerations in the design of the blades is different, however. Because the turbine is removing pressure instead of adding it, there is a favorable pressure gradient. Thus, much more extreme angles are possible without flow separation, and therfore a turbine generally has far fewer stages than a compressor. However, stress on the blades is much higher, due to the more extreme angles and due to the heat of the flow. The buckets must also be able, at these conditions, to withstand the forces of rotation. Indeed, turbine blade design is currently one of the limiting factors on engine design. Buckets must be periodically replaced because they stretch under centrifugal force, a phenomenon known as "creep". Newer methods of casting, including dirctionally solidified and single crystal castings, are used to lessen these problems.