Windmills are machines that use the power of the wind to do work. They have been around for hundreds of years and were first used in Persia (modern-day Iran) around 200 B.C. Since then, windmills have been used for many different purposes such as grinding grain, pumping water, and generating electricity.
Windmills work by using the force of the wind to turn their blades. The blades are attached to a shaft that is connected to a mechanism such as a grinding stone, pump, or generator. As the wind turns the blades, the mechanism inside the windmill is activated and begins to do its work.
There are many different types of windmills. The most common type is the horizontal-axis windmill, which has blades that rotate around a horizontal axis. This type of windmill is used to generate electricity in modern wind farms. Another type of windmill is the vertical-axis windmill, which has blades that rotate around a vertical axis. This type of windmill is often used to pump water.