Podcasting is 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.

While the name was primarily associated with audio subscriptions in 2004, the RSS enclosure syndication technique had been used with video files since 2001, before portable video players were widely available. In fact, any file with a URL, including still images and text, can be delivered as an enclosure.

Use of "podcast" to describe both audio and video feeds seemed natural to some users, while others preferred to reserve the word for audio and coin new terms for video subscriptions. Other "pod-" derived neologisms include "podcasters" for individuals or organizations offering feeds, and "podcatchers" for special RSS aggregators with the ability to transfer the files to media player software or hardware.

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.