RSS stands for Really Simple Syndication, but you can also think of it as "Really Simple Subscription". Subscribing to a podcast is very much like subscribing to a newspaper or magazine. You only subscribe once, and then new issues arrive on your doorstep on a set interval without you having to request them. Likewise, with a podcast you do not have to go out to a website each time you want to listen to or watch the files that make up the podcast. The RSS program automatically downloads those files for you. The one big difference with a podcast is that your subscription never expires. You will keep receiving new episodes until you tell your program to stop downloading them.
An RSS feed consists of a link to an RSS file (you can see an example of one here), a simple text file saved as .xml that stores information about the individual audio or video files that make up the episodes for the podcast. You can't have a podcast that other people can subscribe to without also having this file somewhere on your server.
The RSS file contains special tags (very similar to HTML tags) that hold information about each individual episode, such as its title, a brief summary, and of course a link to the internet address where these audio or video files can be found so that they can be downloaded. You can create the RSS file by typing in the XML code yourself, or you can use a program such as VODCaster. Once you have created the RSS file, you can use a validator, such as this one, to make sure the file follows the RSS specifications.
