A watch is a small timepiece intended to be carried or worn by a person. It is designed to keep working despite the motions caused by the person's activities. A wristwatch is designed to be worn on a wrist, attached by a watch strap or other type of bracelet. A pocket watch is designed for a person to carry in a pocket.
Watches evolved in the 17th century from spring-powered clocks, which appeared as early as the 14th century. During most of its history the watch was a mechanical device, driven byclockwork, powered by winding a mainspring, and keeping time with an oscillating balance wheel. In the 1960s the electronic quartz watch was invented, which was powered by abattery and kept time with a vibrating quartz crystal. By the 1980s the quartz watch had taken over most of the market from the mechanical watch.