Think of it as a bookmark that automatically updates itself to let you know when the site it links to has been updated.

To receive an RSS feed, you either need an RSS capable browser (like Firefox) or an RSS Reader. Adding the feed is different for each browser/program, however, I find the easiest way is to use the Firefox browser and in the bottom right corner, you should see this icon . Click it and it allows you to save the feed as a bookmark. Done!

For other RSS readers and a bit more info, click here.