PODCASTS

A podcast is a series of digital media files (either audio or video) that are released episodically and downloaded through web syndication. The mode of delivery is what differentiates podcasts from other ways of accessing media files over the Internet, such as simple download or streamed webcasts: special client software applications known as podcatchers (like iTunes, Zune, Juice, and Winamp) are used to automatically identify and download new files in the series when they are released by accessing a centrally-maintained web feed that lists all files associated with the series. New files can thus be downloaded automatically by the podcatcher and stored locally on the user's computer or other device for offline use, giving simpler access to episodic content.
Most dictionary definitions of a podcast fall into one of two camps as of September 2009. One set focuses on the "on-demand" nature of podcasts. Another set requires the automatic or syndication posting. There are problems with both definitions. The first is too open. Under such a definition, a paid music download could technically be a podcast. Most audiences would disagree. The second is very limiting, in comparison. It does not allow for manual downloads. Researchers at the Center for Journalism and Communication Research at the University of Texas at Austin are proposing a four-part definition of a podcast: A podcast is a digital audio or video file that is episodic; downloadable; program-driven, mainly with a host and/or theme; and convenient, usually via an automated feed with computer software.
The term podcast refers to an ongoing series or episodes of a particular program. A podcaster is the person who creates the content.

The term "Podcasting" was first mentioned by Ben Hammersley in The Guardian newspaper in a February 2004 article, along with other proposed names for the new medium. It is a portmanteau of the words "Pod" - derived from iPod- and "broadcasting". To avoid a term similar to "iPod", some use the term Netcast instead of Podcast.
It has never been necessary, despite the source of the name, to use an iPod or any other form of portable media player to use podcasts; the content can be accessed using any computer capable of playing media files. A backronym has been posited where podcast stands for "Personal On Demand broadCAST". The term "Podcasting" was first mentioned by Ben Hammersley in The Guardian newspaper in a February 2004 article, along with other proposed names for the new medium. It is a portmanteau of the words "Pod" - derived from iPod- and "broadcasting". To avoid a term similar to "iPod", some use the term Netcast instead of Podcast.
It has never been necessary, despite the source of the name, to use an iPod or any other form of portable media player to use podcasts; the content can be accessed using any computer capable of playing media files. A backronym has been posited where podcast stands for "Personal On Demand broadCAST".

Podcasting began to catch hold with the public in late 2004, though during the 1998–2001 dot-com era there were multiple "podcasts" done by major companies, such as Real Networks and ESPN.com. Many individuals and groups[who?] contributed to the emergence and popularity of podcasts.
The most common audio file format used is MP3.