A podcast is a collection of digital media files which is distributed over the Internet using syndication feeds for playback on portable media players and personal computers. Such syndication is often represented by an RSS icon like those below:.

These files may be composed of either audio and/or video. Often audio podcasts are referred to as as Podcast while video forms are referred to at a Vodcast. The term, like "radio", can refer either to the content itself or to the method by which it is syndicated; the latter is also termed podcasting.

The term "podcast" is a portmanteau of the acronym "Pod" – standing for "Portable on Demand" – and "broadcast". The iPod name was coined with Pod, prefixed with the "i" commonly used by Apple for its products and services. The first podcasting scripts were developed for the Apple’s i-Pod. These scripts allow podcasts to be automatically transferred to a mobile device after they are downloaded. In Apples case this is accomplished through use of the Apple i-Tunes Service. Other similar services including Microsoft’s Zune Service offer similar features. In addition, there are also many free software applications often referred to Podcatchers that offer similar subscription and content management features.

Though podcasters' web sites may also offer direct download or streaming of their content, a podcast is distinguished from other digital media formats by its ability to be syndicated, subscribed to, and downloaded automatically when new content is added, using an aggregator or feed reader capable of reading feed formats such as RSS or Atom.