An MP3 file that you can download, stream over the internet or subscribe to via RSS
General Features
A podcast is a digital media file, or a related collection of such files, which is distributed over the Internet using syndicationfeeds for playback on portable media players and personal computers. The term, like "radio", can refer either to the content itself or to the method by which it is syndicated; the latter is also termed podcasting. The host or author of a podcast is often called a podcaster.
Though podcasters' web sites may also offer direct download or streaming of their content, a podcast is distinguished from other digital media formats by its ability to be syndicated, subscribed to, and downloaded automatically when new content is added, using an aggregator or feed reader capable of reading feed formats such as RSS or Atom.
Pros
Captures the warmth of the human voice
Low-cost
Measurable reach
Portable
Time shift-able
Audience can participate via audio comments and/or text comments on the show's blog
Cons
A loyal audience tends to expect new episodes on a regular basis
Content of a podcast depends on the host(s) knowledge and research