HTML and XML will work with CSS so that you can control presentation more effectively. The difference with XML is that you can associate styles with structural elements that mean something. CSS offers limited control of presentation, handling font changes and such. Multidimensional documents will need to have multiple style sheets, reflecting different views or different devices. The Server-Independent Document XML helps to establish documents that can function independently of the server.
Documents can reside locally once downloaded and continue to function.
For instance, if you download the document to a laptop, you can use the document effectively while not connected to the network. Let's continue with the Address book application. The interface for this application might be an alphabetical list of names. When you click on a name, you get an expanded listing for the person whose name you selected. Using the Document Object Model, you could create a single XML document that contains the entire list of names, addresses and email addresses.