A podcast is a series of digital media files that are distributed over the Internet using syndication feeds (subscriptions). These media files can be audio, video, PDF, text, or other formats. You can then play, watch, or read these files on your computer or other device. The term podcast (like broadcast), can refer either to the series of content itself or to the method by which it is syndicated. This syndication is also called podcasting. The author of a podcast is often called a podcaster. Learn more about podcasting on Wikipedia.
Here is a short video that explains podcasting in plain English:
The Church has created a number of podcasts that you can subscribe to at rss.lds.org. You can also find many other Church-related podcasts at the iTunes store. Just search for “mormon” or “lds.”