RSS stands for Really Simple Syndication. It's a way of separating web content from the websites they came from and allowing people to mix content from different sites or to receive content as soon as it is updated. RSS documents, known as "feeds" or "channels", includes full or summarized text, plus metadata (information about information) such as publishing dates and authorship.
RSS feeds can be incorporated into other sites, or read using software called "RSS readers" or "aggregators", which can be web-based, desktop-based, or mobile-device-based. A standardized XML file format allows the information to be published once and viewed by many different programs.