Podcasting is essentially the same as downloading, but with the added element of syndication technology, which delivers the sound file to the client workstation automatically as part of a subscription.
Syndication protocols (such as RSS and Atom) allow users to subscribe to weblogs and other online content. The subscriptions are known as ``feeds,'' and they are read by using a news- or feed-reader. At particular intervals, the reader makes a call to the server that provides the feed to see if there is new content that can be retrieved. If so, it is automatically downloaded to the client workstation.
In the case of weblogs, the content of a feed is usually text-based; podcasts are the audio equivalent--an audio feed. Because these audio files are often loaded onto iPods and other MP3 players for listening once they have been downloaded, the process has been termed podcasting.
Podcasting technology allows inexpensive, quick, and easy distribution of audio content. Because the audio is downloaded to the client workstation, however, most podcasts consist of noncommercial content--spoken commentary, movie reviews, travelogues, idle observations on life--and steer clear of musical content because of intellectual property issues. Several universities are now using podcast technology as a means of distributing lectures and other noncommercial course-related audio content through an Apple project called iTunes U.