From http://www.w3schools.com (Copyright Refsnes Data)
XLink defines a standard way of creating hyperlinks in XML documents.
XPointer allows the hyperlinks to point to more specific parts (fragments) in the XML document.
Before you continue you should have a basic understanding of the following:
If you want to study these subjects first, find the tutorials on our Home page.
The XML Linking Language (XLink) became a W3C Recommendation 27. June 2001.
The XML Pointer Language (XPointer) became a W3C Recommendation 25. March 2003.
You can read more about XML standards in our W3C tutorial.
The browser support for XLink and XPointer is minimal.
There is some XLink support in Mozilla 0.98+, Netscape 6.02+, and Internet Explorer 6.0. Earlier versions of all of these browsers have no XLinks support at all!
From http://www.w3schools.com (Copyright Refsnes Data)