A podcast is a series of audio or video digital media files which are distributed over the Internet by syndicated download, through Web feeds, to portable media players and personal computers. Like the term broadcast, podcast can refer either to the series of content itself or to the method by which it is syndicated; the latter is also called podcasting. The host or author of a podcast is often called a podcaster.

Podcasting is a term that was devised as a crisp way to describe the technology used to push audio content from websites down to consumers of that content, who typically listen to it on their iPod or other audio player that supports mp3 at their convenience. The term podcasting is meant to rhyme with broadcasting and is a derivative of the iPod platform. While not directly associated with Apples iPod device or iTunes music service, the company did contribute both the desire and the technology for this capability. Podcasting is not unlike 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 push any kind of file, including software updates, pictures, and videos.

Podcasting uses an XML-based technology called RSS, or Really Simple Syndication. Content publishers describe new content in an XML RSS file which includes dates, titles, descriptions, and links to MP3 files. This auto-generated file is called an RSS feed. The key to making podcasting work with RSS is enclosures, a feature supported by RSS 2.0.