What is a Podcast?

I sent this as an email to members of my mailing list as I had people asking me what a podcast was.
Apologies if you find it a little patronising.

Ok in a nutshell a podcast is a piece of audio, usually speech perhaps with some music. Like a radio broadcast. This piece of audio has to be posted on the web so that people can hear it. You can download this podcast to your computer so that you can either add it to your MP3 player (iPods etc) or play it later. If you have an application called iTunes then you can use that to download it. You can subscribe to a podcast so that every time a new one appears, you will automatically download it.
You can also just listen to it from its source (stream).
My latest podcast has just gone live. You can stream it OR download it from http://nicktann.podbean.com. It's about 17 minutes long and has me chatting a bitr and playing 2 songs from some fantastic independent artists that I have discovered.