At its most basic, podcasting is a method for delivering audio (and now video) over the Internet. An MP3 file is placed on the web for listeners to download and listen to on their computer or portable MP3 — an iPod being a prime example of a portable MP3 player, thus the “podcasting” term.

So what’s the difference between an MP3 and a podcast? At the audio level, nothing. The difference is in the delivery. You can place an MP3 on your site, and say that you have a “podcast” — and many people are doing just that. But to really qualify the file as a “podcast” requires setting it up so that it can be accessed via an RSS feed, whether from your site, the iTunes site, or some other RSS host/directory server.

This isn’t the same as “streaming,” where a file plays back from a server. With podcasting, the MP3 file is downloaded by the listener onto their hard drive. At that point, the listener can play it on his or her computer, or choose to transfer it over to their MP3 player to listen to while on the go.

RSS stands for “Really Simple Syndication” — this is the same technology as bloggers use for publishing their “web logs.” You “enclose” the location of your MP3 podcast file in a RSS document — there are several ways to create this document, as we’ll learn on the next page — which can then be found and managed using a small application called an “aggregator” or an “RSS Reader.”

The aggregator or reader “subscribes” to a particular URL where the RSS file is located, and finds any podcasts that are referenced by that RSS file. Since the aggregator subscribes to the RSS “feed,” it will check back each time you launch it to see if there are any new podcasts available. This allows you to do a daily, weekly, or monthly podcast — even hourly or more often, if you like, and have listeners automatically made aware of it.

Aggregators, or readers, can find RSS news feeds, podcasts, video podcasts, or, the latest: some manufacturers are making software updates/downloads available using RSS. An example is the RSS feed Sweetwater has set up for our daily inSync online music industry news. If you subscribe to the inSync RSS feed using an aggregator, the aggregator will check each day, find each day’s new issue of inSync, and make it available to you to read.