Wind power is the conversion of kinetic energy in the wind to electrical energy.
In order to generate electricity, two things are needed:
The flow of electrons could occur in one of two ways:
These are the main components of large utility-scale turbines. However, most residential-scale turbines do not have pitching blades, yaw drives, or controllers. The smaller turbines have stationary blades and utilize passive yaw control sometimes with a tail or through a downwind design (blades are downwind of the tower). Not all turbines have a gearbox, many manufacturers are eliminating this component and focusing on direct drive systems to increase efficiency and decrease maintenance costs. The Department of Energy has a great video showing how large scale wind turbines work. They have also published a tool that shows how distributed (residential and community-scale) turbines work.
Wind turbine blades work on the principle of lift – like an airplane. As the wind passes over the blade, high and low pressure systems are formed due to differences in the speed of the wind passing over the blade. This creates lift and causes the blades to rotate. HowStuffWorks.com has a good tutorial covering wind turbine aerodynamics and the lift principle.
The Department of Energy has more detailed lessons on how wind turbines work.