RSS is an easy way to keep up to date with the web sites important to you. If you already have an RSS reader, just click the orange icon. 
Many programs have an RSS reader built in. If you use Mozilla Firefox as your web browser, for example, you can simply click the orange icon in the address bar and it will automatically add the RSS feed.
For a more detailed explanation of what RSS is and how to get an RSS reader, see this article by the BBC.