A steam turbine, as we see from its name, uses steam to rotate its blades. The rotary motion of the blades is used to rotate the armature of the generator, and the movement of the armature in a magnetic field results in the production of a current (electricity) in the armature! The steam turbine has come a long way from its initial design: there is the single flow steam turbine, the multiple flow steam turbine, the reaction steam turbine, the impulse-reaction steam turbine, and the impulse turbine. It has been the object of research and interest of many engineers and scientists like De Laval, Parson, and Curtis. Heat energy from a coal thermal power plant or a nuclear power plant is used to boil waiter, and convert it into steam at high pressure. This high pressure steam is directed to the turbine blade thus causing the blade to rotate!

The basic turbines of today use a combination of the reaction type and impulse type turbines for higher efficiency.