Clockwork means the inner workings of mechanical machines clocks (where it is also called a "movement". Also other similar mechanisms with a complex series of gears.[1][2][3][4]
A clockwork mechanism usually has a clockwork motor.[5] This has a mainspring, a spiral of metal ribbon. Energy is stored in the mainspring by winding it up, turning a key attached to a ratchet which twists the mainspring tighter. Then the force of the mainspring turns the clockwork gears, until the stored energy is used up. The adjectives wind-up and spring-powered refer to mainspring-powered clockwork devices. These include clocks and watches, kitchen timers, music boxes, and wind-up toys.