Windmills are machines that are driven by wind. Their blades have slightly diagonal surfaces. If the wind hits them from front, they deflect it to the side and in this way convert the wind pressure in a rotary movement. Initially, millers had to set the blades themselves in such a way that the wind came onto them from the front. The rotary movement of the blades gets transferred to the milling stones inside the mill through cogwheels. Windmills were traditionally used to mill corn to make flour and grate spices. They also acted as drive for oil presses and sawmills.
