According to Wikipedia Podcasting is,

"A podcast is a media file that is distributed over the Internet using syndication feeds, for playback on portable media players and personal computers.^[1] Like 'radio', it can mean both the content and the method of syndication. The latter may also be termed podcasting. The host or author of a podcast is often called a podcaster. The term "podcast" is derived from Apple's portable music player, the iPod. Known synonyms for the word pod are capsule, case, container, hull, husk, shell, and vessel.^[2] A pod refers to a container of some sort and the idea of broadcasting to a container or pod correctly describes the process of podcasting.^[3] More about the name itself can be found in the History of podcasting article."

Instead of written content podcasting refers to the distribution (syndication) of files. Often music, video, pdfs, and other documents are pushed out. The difference between standard downloading we are all accustomed to and podcasting is that content is syndicated using RSS much like a blog syndicates to feed readers.

There may be little real estate agent use for this type of technology but I thought I would address it briefly. Some applications for the technology might be for users interested in updated photos of your area, ongoing virtual tour releases, movies about property, etc.