RSS (Really Simple Syndication) is a family of Web feed formats used to publish frequently updated content such as blog entries, news headlines, and podcasts. An RSS document (which is called a "feed" or "web feed" or "channel") contains either a summary of content from an associated web site or the full text. RSS makes it possible for people to keep up with web sites in an automated manner that can be piped into special programs or filtered displays.

RSS content can be read using software called an "RSS reader", "feed reader" or an "aggregator". The user subscribes to a feed by entering the feed's link into the reader or by clicking an RSS icon in a browser that initiates the subscription process. The reader checks the user's subscribed feeds regularly for new content, downloading any updates that it finds. Webmasters also subscribe to RSS feeds and publish feed content on their websites to add value and content to their website.

Most modern internet browsers such as Internet Explorer 7, Firefox and Safari have built in RSS readers while older and obsolete browsers such as Internet Explorer 6 and Netscape browsers do not support RSS formats. Users with older browsers must install third party Feed Readers in order to enjoy the benefits of RSS.

The initials "RSS" are used to refer to the following formats:

• Really Simple Syndication (RSS 2.0)
• RDF Site Summary (RSS 1.0 and RSS 0.90)
• Rich Site Summary (RSS 0.91).

RSS formats are specified using XML, a generic specification for the creation of data formats. Although RSS formats have evolved since March 1999, the RSS icon ("") first gained widespread use in 2005/2006.