a “radio-style” program, usually in the MP3 digital format, disseminated over the Internet, that includes a system for subscribing to it on a World Wide Web page in such a manner that future programs are automatically downloaded. Subscribers typically transfer downloaded files to their portable media players, such as Apple Inc.'s iPod and the Microsoft Corporation's Zune, for later playback. The name podcast derives from a combination of iPod and broadcast.

An early impetus for podcasts came from amateurs who produced their own special-interest programs, but podcasts really took off about mid-2005 when Apple's iTunes online store added tens of thousands of podcasts to its offerings. Many commercial radio and television programs now produce podcasts, which have attracted millions of subscribers.