A windmill is a tall structure with large blades that spin in the wind to create power. Traditional windmills look like towers with four or more enormous arms stretching out from the top, each covered with cloth or wood panels to catch the breeze. As wind pushes against these blades, they rotate, and that spinning motion powers machinery inside the building.

For centuries, windmills were crucial technology for farming communities. Farmers used them to grind grain into flour: the spinning blades turned heavy millstones that crushed wheat and corn. Others pumped water from underground wells or drained marshes to create farmland. The Netherlands became famous for its thousands of windmills, which helped turn swampy lowlands into fertile fields.

While old-fashioned windmills still stand in many places as historical landmarks, modern wind turbines work on the same principle but generate electricity instead. These sleek white towers with three thin blades now dot hillsides and plains across the United States, turning wind into power for homes and businesses.

The phrase tilting at windmills means fighting imaginary enemies or pursuing a foolish quest. It comes from the novel Don Quixote, where the confused knight attacks windmills, thinking they're giants. When someone accuses you of tilting at windmills, they're suggesting you're wasting energy on a problem that doesn't really exist.