A pager, also known as a beeper or bleeper,^[1] is a wireless telecommunications device that receives and displays alphanumeric or voice messages. One-way pagers can only receive messages, while response pagers and two-way pagers can also acknowledge, reply to, and originate messages using an internal transmitter.^[2] In Japanese, it was commonly called a pocket bell (ポケットベル, poketto beru) or pokeberu (ポケベル),^[3] which is an example of wasei-eigo.

Pagers operate as part of a paging system which includes one or more fixed transmitters (or in the case of response pagers and two-way pagers, one or more base stations), as well as a number of pagers carried by mobile users. These systems can range from a restaurant system with a single low power transmitter, to a nationwide system with thousands of high-power base stations.