The Serial podcast being played through an iPhone
A podcast is an episodic series of digital audio or video files which a user can download and listen to. It is often available for subscription, so that new episodes are automatically downloaded via web syndication to the user's own local computer, mobile application, or portable media player.
The word arose as a portmanteau of "iPod" (a brand of media player) and "broadcast". Thus, the files distributed are in audio format, but may sometimes include other file formats such as PDF or ePub. Videos which are shared following a podcast model are called video podcasts or vodcasts.
The distributor of a podcast maintains a central list of the files on a server as a web feed that can be accessed through the Internet. The listener or viewer uses special client application software on a computer or media player, known as a podcatcher, which accesses this web feed, checks it for updates, and downloads 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 though new episodes are broadcast or "pushed" to them. Files are stored locally on the user's device, ready for offline use. There are many different mobile applications available for people to use to subscribe and listen to podcasts. Many of these applications allow users to download podcasts or stream them on demand as an alternative to downloading. Many podcast players (apps as well as dedicated devices) allow listeners to skip around the podcast and control the playback speed.
Some have labeled podcasting as a converged medium bringing together audio, the web, and portable media players, as well as a disruptive technology that has caused some people in the radio business to reconsider established practices and preconceptions about audiences, consumption, production, and distribution. Podcasts are usually free of charge to listeners and can often be created for little to no cost, which sets them apart from the traditional model of "gate-kept" media and production tools. Podcast creators can monetize their podcasts by allowing companies to purchase ad time, as well as via sites such a Patreon, which provides special extras and content to listeners for a fee. It is very much a horizontal media form: producers are consumers, consumers may become producers, and both can engage in conversations with each other.
"Podcast" is a portmanteau, invented by BBC journalist Ben Hammersley in 2004, of the words "pod" — from iPod, a popular brand of portable media player produced by Apple Inc. — and "broadcast". Despite the etymology, the content can be accessed using any computer or similar device that can play media files. Use of the term "podcast" predated Apple's addition of formal support for podcasting to the iPod, or to Apple's iTunes software.
Other names for podcasting include "net cast", intended as a vendor-neutral term without the loose reference to the Apple iPod. This name is used by shows from the TWiT.tv network. Some sources have also suggested the backronym "portable on demand" or "POD", for similar reasons.
Main article: Uses of podcasting
Communities use collaborative podcasts to support multiple contributors podcasting through generally simplified processes, and without having to host their own individual feeds. A community podcast can also allow members of the community (related to the podcast topic) to contribute to the podcast in many different ways. This method was first used for a series of podcasts hosted by the Regional Educational Technology Center at Fordham University in 2005. Gronstedt explores how businesses like IBM and EMC use podcasts as an employee training and communication channel.