figure 1.1

RSS is an XML-based (eXtensible Markup Language) language used to describe the content of an article. Another way to describe an RSS file is that it is just raw meta-data (data about data) about a particular document. If you have created a Web page, you should be familiar with the tag. This meta-data usually includes information such as a brief description of the document and keywords that should be used to index the document. RSS takes that to the next level.

Depending on the version of RSS being used, the file may contain different amounts of information. There are currently four different and somewhat competing versions of RSS being used on the Web: 0.91, 0.92, 1.0 and 2.0. For a good discussion of the differences I suggest you pick up a copy of Content Syndication with RSS by Ben Hammersley.