Podcasting (so named because the majority of MP3 devices seem to be iPods, although any MP3 capable device is able to listen to “podcasts”) is all about recording a radio-style audio file, saving it in (usually) MP3 format and putting it on the web for people to download and listen to at their convenience. It’s kind of like what VCRs did for television in the 80s…. It’s unshackled radio from the confines of the fixed time, “broadcast” medium, not to mention that it has enabled thousands of ordinary people to “have a voice” and broadcast some fairly niche interests to an often equally receptive niche audience.

The real social power of podcasting comes from enabling all those thousands of people to have their say without the need to apply for a broadcasting license or all the other red tape and rules that would normally prevent someone from getting an airing. It truly is helping democratize the way people are able to express themselves. Blogging is essentially doing the same thing, except in a written medium, rather than an audio one.

But the other aspect of podcasting that makes it so powerful is a little thing called RSS, or Really Simple Syndication. In a nutshell, this means that each podcast (or blog for that matter) has a small piece of code in it that can be read by a program called an RSS aggregator. In the case of podcasts, the best known aggregator would probably be Apple’s iTunes software, and it enables a user to subscribe to one of these feeds and have it automatically delivered to your computer every time a new episode is released.

If I could give you an analogy, imagine if you could nominate (subscribe to) your favourite TV shows, and then each time a new episode was released it would be automatically delivered to your television and saved for later viewing, without you having to actually think about when and where it was being shown.

The digital sound files used for podcasting are exactly the same as those used for regular digital audio, the main difference is that they come wrapped in these “RSS enclosures”, to enable the whole subscribing thing to work.

(Thanks to Elham J for asking this question!)