When you click that RSS link, it downloads a file that you can then import into your RSS reader of choice. It's just a easy to aggregate anything you'd want to read via RSS (think of it like your own personal magazine subscription). If you mod a community you could set it up to get notifications when someone posts through that same reader application.

Any site that generates content can choose to create an RSS feed. Essentially it's a link to which the site can push new stories.

You need an RSS client. Good news! There are a lot of free ones (and open source, too!).

The pro's of RSS:

• all your different go-to news outlets in one place
• no ad-ridden webpages
• no dealing with interfaces of said news outlets
• your pick ff categories, for instance if you're not interested in celebrity gossip, you just turn that off

The cons:

• you'll need to go collect RSS links from your favorite sites
• one of your sites might no longer use RSS because they don't get ad revenue for it
• RSS readers are often not pretty
• you might get weirdly formatted text pages sometimes

Some guides on openrss.org may be helpful