A podcast is a type of digital media consisting of an episodic series of audio, video, PDF, or ePub files subscribed to and downloaded through web syndication or streamed online to a computer or mobile device. The word is a neologism derived from “broadcast” and “pod” from the success of the iPod, as audio podcasts are often listened to on portable media players.
A list of all the audio or video files currently associated with a given series is maintained centrally on the distributor’s server as a web feed, and the listener or viewer employs special client application software, known as a podcatcher, that can access this web feed, check it for updates, and download any new files in the series. This process can be automated so that new files are downloaded automatically, which may seem to the user as if the content is being broadcast or “pushed” to them. Files are stored locally on the user’s computer or other device ready for offline use, giving simple and convenient access to the content. Podcasting contrasts with webcasting (Internet streaming), which generally isn’t designed for offline listening to user-selected content.
As discussed by Richard Berry, podcasting is both a converged medium bringing together audio, the web and portable media player, and a disruptive technology that has caused some in the radio business to reconsider some of the established practices and preconceptions about audiences, consumption, production and distribution.