RSS - Really Simple Syndication - is a way to gather headlines from your favourite sites that offer web feeds. Sites that have this icon 
allow a reader to 'subscribe' to the feed and the viewer can then use a program called an RRS reader or aggregator that 'reads' and organizes the feed.
The RSS reader checks the user's subscribed feeds regularly for updates and provides a user interface to monitor and read the feeds.
So how do you use it? You could put your favorite web site’s RSS feed (digg and slashdot are two good examples) on your iGoogle page. Then you could see the latest headlines at a glance and decided which if any you wanted to read more about.
Here are some interesting ways to use RRS feeds:
1. Create an RSS favorite of the local jobs list on Craig’s List . Then select a folder from your favorites bar in Firefox. The list is updated every 15 (or whatever you specify) minutes.
2. iTunes for instance uses RSS extensively for things like podcast feeds.
Subscribe to blogs usingBloglovin' or Feedly - http://xomisse.com/blog/blog-tips-ultimate-guide-to-bloglovin/
http://www.purrdesign.com/articles/life-after-google-reader/
http://www.accordingtoelle.com/2012/12/bloglovin-tutorial/
Create a Feed
a free blogger/wordpress site
Readers
Firefox - a good article on adding and reading feeds: http://johnbokma.com/firefox/rss-and-live-bookmarks.html
Feeddemon at Newsgator - works with PBworks and other private sites.