[A] term coined in 2004 when the use of RSS syndication technologies became popular for distributing audio content for listening on mobile devices and personal computers. A podcast is a web feed of audio or video files placed on the Internet for anyone to subscribe to. Podcasters' websites also may offer direct download of their files, but the subscription feed of automatically delivered new content is what distinguishes a podcast from a simple download or real-time streaming (see below). . . . Podcasting's essence is about creating content (audio or video) for an audience that wants to listen when they want, where they want, and how they want.
Some podcasts update their listings every few hours (like NPR), others update daily, weekly, or at more random intervals. You can tap into great political coverage, world news coverage, audiobooks, music, comedy shows, and just about anything--all with no or very few advertisements. Most podcasts are free, but some require payment.