The term podcasting plays upon the terms broadcasting and webcasting and is derived from the name of the iPod portable music player, the playback device of choice of many early podcast listeners. While not directly associated with Apple's iPod device or iTunes jukebox software, the company did contribute both the desire and the technology for this capability. Podcasting is similar to time-shifted video software and devices like TiVo, which let you watch what you want when you want by recording and storing video, except that podcasting is used for audio and is currently free of charge. Note, however, that this technology can be used to pull any kind of file, including software updates, pictures, and videos.
In short, podcasting involves the recording of internet radio or similar internet audio programs. These recordings are then made available for download to your iPod or other portable digital audio device. You can listen to the podcast internet radio program while you are away from your computer or at a different time than the original program was broadcast.
Podcasting - Wikipedia, the free encyclopedia