According to
http://en.wikipedia.org/wiki/Podcast :
"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. 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 host or author of a podcast is often called a podcaster."
And -
http://www.antsmarching.org/podcast