Podcasting is a method to automatically distribute content over the internet to subscribers. What this means is that you can have things such as recordings or handouts from your class lectures automatically sent to your students for them to view on their computer or handheld devices. If you'd prefer a more abstract answer you might ask a ninja.

Unlike posting content on a web page, when you podcast content a viewer can "Subscribe" and have all future content in the podcast automatically sent to their computer. This is all possible because of something called RSS which stands for Really Simple Syndication. You can create podcasts using dedicated podcasting software, or by creating a blog that publishes an RSS feed. There are lots of free blogging services that will work.

The term "podcast" comes from the fact that audio or video content included in a podcast can be downloaded to an iPod for mobile viewing, however many viewers choose to view heir podcasts on their computer rather than on a portable device.