xlink, xpointer, xml, xciting....

I learned quite a bit about XML in IRLS 515 last semester. But of course questions remained. One big one was answered by the following section from http://www.w3schools.com/xml/xml_usedfor.asp :

"--XML Separates Data from HTML

If you need to display dynamic data in your HTML document, it will take a lot of work to edit the HTML each time the data changes.

With XML, data can be stored in separate XML files. This way you can concentrate on using HTML for layout and display, and be sure that changes in the underlying data will not require any changes to the HTML.

With a few lines of JavaScript code, you can read an external XML file and update the data content of your web page. "

As fits best with my learning style, my remaining questions were best answered by searching online myself. I was wondering, how do you link xml and html documents together? I saw the examples of xml docs enhanced with css, and I know how to do that, but what about adding links and such? How do you link a photograph to its xml description?

Of course my question sent me right back to the W3schools site, to the xlink and xpointer tutorial. I'm working through it currently but you'll see a link to my use of it if I ever get there!