A turbine, like the ones in a wind farm, is a machine that spins around in a moving fluid (liquid or gas) and catches some of the energy passing by.
Simply stated, a wind turbine works the opposite of a fan. Instead of using electricity to make wind, like a fan, wind turbines use wind to make electricity.
The huge rotor blades on the front of a wind turbine are the "turbine" part. The blades have a special curved shape, when wind blows past a turbine's blades, it spins them around instead.
The wind turns the blades, which spin a shaft, which connects to a generator and makes electricity.