Podcast
From the ChristianMedia.ca GlossaryFrom David Spencer's Media Spin Glossary Resources: Culture | Dance | Film | Music | New Media | News | Performing Arts | Publishing | Radio | Television | Visual Arts | Writing
A podcast is a multimedia file distributed over the Internet using syndication feeds, for playback on mobile devices and personal computers. The term, as originally coined by Ben Hammersley in an article in the Guardian February 12, 2004 [1], was meant as a portmanteau of "broadcasting" and "iPod".[2] Like 'radio', it can mean both the content and the method of delivery; the latter may also be termed podcasting. The host or author of a podcast is often called a podcaster. Though podcasters' web sites may also offer direct download or streaming of their content, a podcast is distinguished from other digital audio formats by its ability to be downloaded automatically using software capable of reading feed formats such as RSS or Atom. The concept of podcasting was suggested as early as 2000 and its technical components were available by 2001, then implemented in the program Radio Userland[3]. In 2003 regular podcasts started showing up on well-known Web sites and software support spread. The publish/subscribe model of podcasting is a version of push technology, in that the information provider chooses which files to offer in a feed and the subscriber chooses among available feed channels. While the user is not "pulling" individual files from the Web, there is a strong "pull" aspect in that the receiver is free to subscribe to (or unsubscribe from) a vast array of channels. Earlier Internet "push" services (e.g., PointCast) allowed a much more limited selection of content. Podcasting is an automatic mechanism whereby multimedia computer files are transferred from a server to a client, which pulls down XML files containing the Internet addresses of the media files. In general, these files contain audio or video, but also could be images, text, PDF, or any file type. The content provider begins by making a file (for example, an MP3 audio file) available on the Internet. This is usually done by posting the file on a publicly-available webserver; however, BitTorrent trackers also have been used, and it is not technically necessary that the file be publicly accessible. The only requirement is that the file be accessible through some known URI (a general-purpose Internet address). This file is often referred to as one episode of a podcast. To conserve bandwidth, users may opt to search for content using an online podcast directory. Some directories allow people to listen online and initially become familiar with the content provided from an RSS feed before deciding to subscribe. For most broadband users, bandwidth is generally not a major consideration; it could fairly be stated that podcasting itself is a technology that came with the increases in global bandwidth and broadband popularity. |
