CSS is a language for thespecification of the layout (position,
size, font, etc.) of different parts of a document, in a specific style
sheet language. They are used to assign style to parts or elements of
documents in the HTML, XML and other formats.
CSS can either be included in
a document or referenced indirectly by the URI for a separate CSS file.
It is also possible to specify that different style sheets are to be used
when presenting a document on different media, such as screen, paper,
etc. By "cascading" is meant that there can be more than one style sheet
for a document, and there are then rules for deciding which of them to
apply to each element in the document.
An advantage with CSS is
that you can specify style information in a single file, and use it in
many documents, and can then change the style of all the documents by
changing in only a single place. A problem is that (when this is written,
May 2000) web browsers do not always support CSS correctly and consistently.