From The Free On-line Dictionary of Computing (27 SEP 03):

Cascading Style Sheets
     
        <World-Wide Web> (CSS) An extension to HTML to allow styles,
        e.g. colour, font, size to be specified for certain elements
        of a hypertext document.  Style information can be included
        in-line in the HTML file or in a separate CSS file (which can
        then be easily shared by multiple HTML files).  Multiple
        levels of CSS can be used to allow selective overriding of
        styles.
     
        Home (http://www.w3.org/Style/CSS/).
     
        (2000-07-26)