Short for 'Really Simple Synication' (also known as Rich Site Summary or RDF Site Summary), refers to a group of XML based web-content distribution and republication (Web syndication) formats primarily used by news sites and weblogs (blogs). Any website can issue an RSS feed. By subscribing to an RSS feed, you are alerted to new additions to the feed since you last read it. In order to read RSS feeds, you must use a "feed reader," which formats the XML code into an easily readable format (feed readers are to XML and RSS feeds as web browsers are to HTML and web pages.