A podcast is a digital audio or audiovisual file, usually updated regularly, that can be downloaded free by a computer user connected to the Internet. Podcasts are provided by news organizations, advocacy groups, radio and TV broadcasts, and individuals. Podcast content ranges from educational, scientific, and religious to pornographic.
Podcast files are stored on webservers (computers dedicated to distributing information to end-users over the Web), from which they are downloaded to computers. They are distinguished from other downloadable digital audio and audiovisual files by the fact that they can be downloaded automatically by programs known as aggregators, podcatchers, and pod-cast receivers. These programs allow the user to specify which podcasts they wish to receive. The program then handles the details of checking periodically for new episodes (individual podcast files) and downloading them. Attaching a personal audio player such as an iPod or Zune to a computer will then result in automatic download of the podcast to the player. Updating may also be done wirelessly. An aggregator need not be, and by 2006 usually was not, a dedicated program: many digital media programs as iTunes
(a free product from Apple Corp.) and the e-mail program Mozilla Thunderbird routinely incorporated aggregator features.
The podcasting phenomenon shows how quickly new cultural practices can arise in connection with computers and the Internet. The concept of podcasting was not proposed by computer experts until late 2000. The first podcasted file, a Grateful Dead song, went online in January, 2001. The practice spread rapidly in 2002 and 2003, but the word “podcast,” an invention of the British journalist Ben Hammersley, was not suggested until February, 2004. Google hits for “podcasts” rose from 24 on September 28, 2004 to 526 six days later and 2,750 three days after that. By October 18, 2004, the word appeared on the Web more than 100,000 times; one year later, more than 100,000,000 times. However, usage of the term seems to have stabilized at about that level: in November, 2006, Google found fewer than 97,000,000 hits for “podcasts.”
The word “podcast” is a conflation of “iPod” (the most popular make of personal audio player at the and still so in 2006) and “broadcasting.” Because this word is so closely associated with a single manufacturer’s product, alternative terms such as blogcasting, audioblogging, and netcasting have been proposed. However, “podcasting” seems firmly established, as of this writing. The claim that “podcast” derives from Personal On-Demand Broadcast is inaccurate, a latter-day invention by a competitor of Apple Corporation, the iPod’s manufacturer.
“Podcast” was declared the Word of the Year in 2005 by the editors of the authoritative Oxford New American Dictionary, Oxford University, United Kingdom. The definition given by that dictionary is “a digital recording of a radio broadcast or similar program, made available on the internet for downloading to a personal audio player.” However, this definition is slightly misleading because a user may choose to listen to (or watch) a podcast on their computer or personal digital assistant rather than on their personal audio player.