A wind turbine is a system that converts the kinetic energy in the wind first into mechanical energy and then into electrical energy. 
A wind turbine generally consists of tower, blades, rotor, gear box, generator (alternator), electrical-electronic components. The kinetic energy of the wind is converted into mechanical energy in the rotor. The rotational motion of the rotor shaft is accelerated and transferred to the generator in the body. The electrical energy obtained from the generator is stored by batteries or transmitted directly to the buyers.
To understand how wind turbines work, two important aerodynamic forces must be well known. These are drag and lift forces.
The drag force is a force that occurs on the body in the flow direction. For example, when the maximum drag force that can occur on a flat plate is when the air flow is 90o perpendicular to the object; The minimum drag force occurs when the air flow is parallel to the surface of the object.
The buoyancy force is a force that occurs perpendicular to the flow direction. It is named as buoyancy because this force causes airplanes to take off from the ground.
The parachute is the best example of drag force. Thanks to this force, the speed of the parachute is reduced. Special objects made to minimize the effects of the drag force are called streamlined objects. Ellipses, fishes, zeppelins can be given as examples of these objects.