Portable timepiece designed to be worn on the wrist or carried in the pocket.
The first watches appeared shortly after 1500, when the mainspring (see spring ) was invented as a replacement for weights in driving clocks . The progressive miniaturization of electronic components in recent decades has made possible the development of all-electronic watches, in which the necessary transistors, resistors, capacitors, and other elements are all on one or several miniature integrated circuits , or chips. Such circuitry enables them to perform several timekeeping functions and also makes possible digital readouts of the time.