2. Podcast? Podcast, which the Oxford American Dictionary named the "Word of 2005," is a media file (usually audio but sometimes video) made available for download to a portable device or personal computer. Podcasts use feeds that let you subscribe to them, so that when a new audio clip is published online, it arrives on your digital doorstep right away. http://www.capilanou.ca/help/login-page/active-cms/glossary.html#Podcast
3. Vodcast? A vodcast is a podcast that contains video content. The term vodcast comes from the combination of the words "video" and "podcast". Video podcasts may also be referred to as vidcasts. In order to watch a vodcast, you need a podcatcher capable of playing video (such as iTunes). http://kb.iu.edu/data/auyt.html