A winch is a machine that pulls heavy objects using a rotating drum wrapped with rope, cable, or chain. Picture a large spool that turns in circles, winding up the rope as it spins, and you've got the basic idea. As the drum rotates, it winds the rope tighter and tighter, creating enough force to drag extremely heavy loads that would be impossible to move by hand.

Winches appear everywhere people need to lift or pull something heavy. Tow trucks use winches to pull damaged cars onto their flatbeds. Ships use anchor winches to raise massive anchors from the ocean floor. Construction workers use winches to hoist steel beams up the sides of buildings. Rock climbers sometimes use portable winches to rescue injured climbers from difficult terrain.

The drum can be turned by an electric motor, a gasoline engine, or even by hand with a crank handle for smaller winches. What makes a winch so powerful is its mechanical advantage: each turn of the drum multiplies your pulling strength many times over. A person turning a hand-cranked winch might be able to pull a thousand-pound boat out of the water, something that would be utterly impossible with muscle power alone. The word can also be used as a verb: when you winch something up, you're using a winch to pull it.