Internet radio (also web radio, net radio, streaming radio, e-radio webcasting) is an audio service transmitted via the Internet. Internet radio services are usually accessible from anywhere in the world.
Internet radio involves streaming media, presenting listeners with a continuous stream of audio that cannot be paused or replayed, much like traditional broadcast media; in this respect, it is distinct from on-demand file serving.
Internet radio is also distinct from podcasting, which involves downloading rather than streaming.
Many Internet radio services are associated with a corresponding traditional (terrestrial) radio station or radio network. Internet-only radio stations are independent of such associations.
Streaming technology is used to distribute Internet radio, typically using a lossy audio codec. Streaming audio formats include "MP3, Ogg Vorbis, Windows Media Audio, RealAudio, and HE-AAC (or aacPlus)". Audio data is continuously transmitted serially ("streamed") over the local network or internet in TCP or UDP packets, then reassembled at the receiver and played a second or two later. The delay is called lag, and is introduced at several stages of digital audio broadcasting.
