A podcast is an internet media file, usually audio or video, that is collected or downloaded to subscribers through a feed reader. Podcasts work kind of like magazines--you pick the subject(s) you're interested in, subscribe to related podcasts, and the podcasts are sent to your computer via a feed or download whenever a new "issue", or rather episode, is uploaded to the feed.
This video explains how podcasts work:
If you are interested in using podcasts in your classroom, check out the pages on Audio and Video Podcasts for searchable podcast directories on many different subjects. There are links for most age/grade levels.
If you are interested in having your students create podcasts, you can
- check out the comprehensive "How-To Guides" by clicking on the tab above, or
- get more information/training by logging in at SimpleK12 and taking some short courses in podcasting. (These can be found in the Level 3-Integrating Technology with Web 2.0 course list.)
- listen to MANY podcasts on many different topics to get an idea of what makes a good podcast and what components you want your students to incorporate (your students should listen to podcasts too!).