Podcasting is a method of publishing files via the Internet, allowing users to subscribe to a feed and receive new files automatically. It became popular in late 2004, intended largely for downloading audio files onto a portable MP3 player. However, listening to podcasts does not require a portable player and it is not traditional "broadcasting" to a mass audience at a fixed time.
"Podcasting" is a portmanteau, combing "broadcasting" with the name of Apple Computer's iPod audio player (although podcasting was not invented by Apple, nor do podcasts require a portable player or Apple software).
It is distinct from other types of online audio delivery because of its subscription model, which uses the RSS 2.0 file format. Podcasting enables independent producers to create self-published, syndicated "radio shows," and gives broadcast radio programs a new distribution channel. Listeners may subscribe to feeds using "podcatching" software (a type of "aggregator"), which periodically checks for and downloads new content. Some podcatching software is also able to synchronise (copy) podcasts to portable music players. Any digital audio player or computer with audio-playing software can play podcasts. The same technique can deliver video files, and by 2005 some aggregators could play video as well as audio.
