The word "podcast" is a concatenation of the words iPod and broadcast. The underlying technology used for podcasts, called RSS (Really Simple Syndication) is capable of containing any type of media including audio, video, graphics, and more.
Podcasting is a way of publishing podcasts to the web, allowing people to subscribe to a podcast and receive new "episodes" automatically through an RSS feed.
Podcasts offer iTunes users and iPod owners the same freedom and level of control they are familiar with when listening to their own personal music collections.
How much do podcasts cost?
All podcasts on the iTunes Music Store are free.
Do I have to have an account at an iTunes Music Store to get podcasts?
No. You can preview and subscribe to podcasts without opening a Music Store account.