Radio broadcasting is an audio (sound) broadcasting service, broadcast through the air as radio waves (a form of electromagnetic radiation) from a transmitter to a receiving antenna. 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.
Internet radio
When Internet-based radio became feasible in the mid-1990s, the new medium required no licensing and stations could broadcast from anywhere in the world without the need for over the air transmitters. This greatly reduced the overhead for establishing a station, and in 1996, George Maat started 'A' Net Station (A.N.E.T.) under the now defunct domain Advice-Net.com, and began broadcasting commercial-free from Antarctica.
MIT developed the "Radio Locator" List of Radio Stations. After stations started streaming audio on the Internet, Radio-Locator added this to their search engine so anyone could locate a station's website and listen to a station offering a worldwide stream. This list also tracks "terrestrial" radio stations who may not have live audio on the net, or even a website, but are able to find station information by various other search queries.
http://en.wikipedia.org/wiki/Radio_broadcasting#Internet_radio
