From Mac Guides
Podcasting is the distribution of media files (originally audio but now also video) over the Internet using RSS syndication, used for purposes such as to distribute radio shows online. Its name was derived from the words "iPod" and "broadcasting", although its creators were not affiliated with Apple nor does the technology require the use of an iPod.
Creating a podcast
Creating and publishing a podcast requires the following:
- Good audio recording equipment
- Good background music (if one prefers to add it)
- Software application to create and publish a podcast
- A server to host the podcast
Since podcasts are usually created as mp3 files, the creator should also keep the bandwidth requirements in mind when choosing a provider to host it.
As of version 4.9, iTunes can be used to subscribe to, download, organize and even publish your podcasts to the iTunes Music Store (check http://www.apple.com/support/garageband/podcasts for information about publishing to the iTunes Music Store). The podcast directory in iTunes lists many popular podcasts.