There are many different possible tree models for XML. The deeper you 
look the more differences you find between DOM, the XML Infoset, XPath 
1.0, XPath 2.0, and other tree-based data models. But it doesn't stop 
there. There are non-tree-based models of XML documents, and these may 
also be profitably used in the right circumstances. XML is defined such 
that it is possible to represent a well-formed document as a tree. It is 
by no means necessary to do so.

SAX exposes probably the most popular non-tree model, but it's hardly 
the only one. Indeed there are non-event, non-tree models as well. Some 
people have shredded XML documents into relational tables. That works 
too. None of these models are more correct than any of the others. It's 
simply a question of which is most useful for the problem at hand given 
the available tools.



-- 
Elliotte Rusty Harold  elharo@m...
XML in a Nutshell 3rd Edition Just Published!
http://www.cafeconleche.org/books/xian3/
http://www.amazon.com/exec/obidos/ISBN=0596007647/cafeaulaitA/ref=nosim