RSS stands for Really Simple Syndication, a way of distributing content online. Subscribers to RSS feeds use a feed reader to gather syndicated content from a variety of sites that interest them. Feed readers can either be stand-alone applications or can be Web-based. (Bloglines and Google News are examples of the latter.)
Whichever reader you use, you can subscribe to our available feeds by clicking on the orange RSS button on pages where it appears or by clicking on the buttons on the Subcribe page. Current Web browsers often show when a site has a feed by displaying a small orange icon in the browser address bar.
Learn more about RSS and aggregators at Wikipedia.