Podcast
A podcast is a series of audio or video files that are periodically released and downloaded to a user's computer or mp3 device. Podcasts are usually delivered through subscription to an RSS feed or through a podcatcher, such as I-Tunes.
Vodcasting
Vodcasting is the online delivery of a video clip through an RSS feed. Although podcast usually refers to digital media files of both audio and video content, the term vodcast is used to distinguish it from files containing only audio.