RSS is a cool technology that makes the lives of us internet users really easy. It stands for Really Simple Syndication. It can contain links to frequently updated content published by a website (in my case the Random Musings blog). It can also be used for pictures ( i.e Flickr), audio files (podcasts), or video (i.e Scoble's Scobeshow) . There are various programs that can subscribe to feeds and automatically check for (and some download) updates that you can view later. Such programs include Internet Explorer 7, various Firefox Extentions, the Google Reader and various other web services such as Bloglines.
You can find complete lists here:
I personally use Google Reader (with Gears for offline reading).
And if you're really stuck, watch this video: RSS in Plain English.