Definition of a pod-cast; A podcast is a pre-recorded audio that is posted to a website and can be made available to download so people can listen to them on their personal computers, ipods/MP3 players or mobiles.
The word podcast is a play on the word broadcast combined with the word iPod however Apple did not invent the word podcast.
Definition of a vod-cast; A vodcast or video podcast is a video stored in a digital form that you can download from the internet and play on a computer or on an MP3 player/Ipod. A vodcast is essentially like a podcast except that you watch it [video] rather than just listen to it.
I was not available to do mine and Megan's first podcast.