External Fax Modem, Intel Corporation, 1993

Modems transmit computer data over telephone lines. They MODulate computer data into sound, and DEModulate it back into translated digital data. Modems held an important role in the home computer revolution. People used them to access information-sharing Bulletin Board Systems, later supplanted by the Internet. Despite abundant wireless Internet availability, "dial-up" modems are popular where DSL and cable services are unavailable.