A Source is a component of BMP which is a means to play back and, depending on its nature, give management control over certain type of media, or certain type of media from a certain location. For example, the Library source is meant for local file playback, while the Podcast source is meant to play, view (for video Podcasts) and manage Podcasts.

A podcast is a digital media file, or a series of such files, that is distributed over the Internet using syndication feeds for playback on portable media players and personal computers. In other words, a podcast is a collection of files (usually audio and/or video) residing at a unique web feed address. People can "subscribe" to this feed by submitting the feed address to an aggregator (like iTunes - software that runs on the consumer's computer). When new "episodes" become available in the podcast they can be downloaded to that user's computer. Unlike radio or streaming content on the web, podcasts are not real-time. The material is pre-recorded and users can check out the material at their leisure, offline.