A clock is a structure or object whose purpose is to broadcast the current time within the local environment, either through visual display or by playing sounds understood to represent the time. This usage applies especially to structures like clock towers, sundials, and bell towers which are used to tell the time.

The indication communicates the current time to the surrounding area. It can be visual or audible, so a clock need not have a conventional numbered face.

Chimes can perform other signaling or musical functions as well as telling the time. A bell installation is a clock only when its sounds communicate the time.