First, RSS stands for Rich Sits Summary, or is sometimes referred to as Really Simple Syndication. It is a service that is used to track recent updates on websites, such as blogs and news reels. This RSS feed contains full or partial content of recent updates, from sites that you chose to subscribe to.
In order to view this feed, however, you have to have an RSS Reader. Most of the online giants have their own (i.e. Google, Yahoo, etc.). Most sites, especially blogs, have a symbol like the one I included above.
Once you download an RSS Reader and subscribe to your favorite sites, you'll have a current view of all the new posts or updates on these sites without going to each one individually. I've included an example of what my feed reader looks like below.
Using Google New RSS Feeds
Here's a helpful how to video showing step by step how to subscribe. Please note that it may not look the same on your computer, depending on your browser and feed reader, but the general concept is the same.