A wind farm uses wind turbines to generate energy. A wind turbine captures energy from the wind and converts it into mechanical energy: Ie, a combination of kinetic (moving) and potential energy. It is able to do this because the wind moving past the blades (arms) of the turbine creates a lift, which pushes them round. The blades are connected to a drive shaft that allows electricity to be generated from the wind energy.
The modern turbine developed from the traditional windmill, one of the oldest machines in history, which also works by capturing and using the energy that naturally comes from moving air. A turbine can be quite small; in fact, small ones are now starting to be used in private homes with a converter to change the captured energy to alternating current.
A wind farm, though, may have several hundred large turbines. Most of them work on a horizontal axis with the rotar blades pointing into the wind, but new vertical axis versions are now being designed too.