It's taken a while for me to realize that RSS ( "Really Simple Syndication" ) is the World Wide Web equivalent of Usenet. It's long been said that the major difference between the Web and the newsgroups are that email is a "one to one" medium (one person writing to one person) and the Web is a "one to many" medium (one Web site being read by many different people), while the newsgroups are a "many to many" medium (many different posters writing messages that are read by many different people). RSS ups the ante by pulling thousands upon thousands of Web sites together into one enormous information flow: the feed. (I like the term "feed" used for RSS: it's a suitably scary science-fictiony term that conjures up images of a vast, flowing stream of "information" that you can tap into and add to. It's a lot more sexy and enticing than saying "I put a file up on my Web site and wait for RSS bots to drop by and read it." )
When you have RSS running on your blog, wiki, journal, or Web site, it allows you to broadcast your blog, wiki, or journal content onto the Web, so that changes and updates to your blog will show up immediately to anyone who is tapped into the RSS feed. What you're actually doing is creating a special file with an .XML extension, which is automaticallly read by hundreds or thousands of RSS "bots" that stop by every so often to see if there have been any updates made to your Web page.
The real advantage of the RSS feed is that you can use an RSS newsreader program such as Bottom Feeder. This will let you keep up with the latest updates on all of your favorite Web sites that use RSS. This includes news sites, music sites, blogs, Livejournals, podcasting sites, online comics, wikis (including this very Web site!)…you can read all of these sites with one news reader program. If you're an information junkie, then RSS is a shot of pure H into your right arm.