The radio

Radio broadcasting is a one-way sound broadcasting service, transmitted overradio waves (a form of electromagnetic radiation) from a transmitter to a receiving antenna and intended to reach a wide audience. Stations can be linked in radio networks to broadcast common programming, either in syndication or simulcast or both. Audio broadcasting also can be done via cable FM, local wire networks, satellite and the Internet.

Broadcasting by radio takes several forms. These include AM and FM stations. There are several subtypes, namely commercial, public and nonprofit varieties as well as student-run campus radio stations and hospital radio stations can be found throughout the world.