Podcasting lets you automatically receive the latest episode of your chosen programme as soon as it’s available. You need to “subscribe” to receive a podcast, rather like you might subscribe to a magazine and get it delivered each week. Most of the Lifestyle PodNetwork’s podcasts are free, and you can stop receiving the files at any time.
In order to sign up for a podcast you need an internet connection and a piece of podcast software which is usually available free of charge. This software can check the Lifestyle PodNetwork for new episodes and automatically download them for you.
For more information you can visit Wikipedia.
Podcasting in Plain English
This is a great video explaining how podcasting works, from Lee Lefevre at Commoncraft.com

