RSS (acronym for Really Simple Syndication) is a method of displaying website content like news or software updates in a standard format.
The XML format can be interpreted by web browsers and by specific applications that will display the news and updates in an way that is easier to understand by end-users.
RSS readers will allow users to create lists of RSS links and to adjust how often the application needs to check for new content.
RSS readers will also offer users the possibility to export their lists to external files (OPML is the most frequent format) that can later be imported within other applications.