From Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Podcasting)

Podcasting, a portmanteau of Apple's "iPod" and "broadcasting", is a method of publishing files to the Internet, often allowing users to subscribe to a feed and receive new files automatically by subscription, usually at no cost. It first became popular in late 2004, used largely for audio files.

Podcasting is distinct from other types of audio content delivery because many people use a subscription model which uses the RSS 2.0 file format. This technique has enabled independent producers to create self-published, syndicated "radio shows", and has given broadcast radio programs a new distribution channel. Some users subscribe to podcasts using "podcatching" software (also called "aggregator" software), which periodically checks for and downloads new content. It can then sync the content to the user's portable music player. Podcasting does not require an iPod or iTunes; any digital audio player or computer with the appropriate software can play podcasts. The same technique can deliver video files, and by 2005 some aggregators could play video as well as audio.

Podcasting is similar to Yahoo!'s Media RSS, a kind of syndication of media files that Yahoo! uses, among other things, to expand the search index of their Yahoo! Video Search engine with video files posted by publishers.