From http://www.w3schools.com (Copyright Refsnes Data)

You Have Learned XLink, Now What?

XLink Summary

This tutorial has taught you a standard way of creating hyperlinks in XML documents.

You have learned that linking in XML is divided into two parts: XLink and XPointer.

XLink defines a standard way of creating hyperlinks in XML documents and XPointer allows the hyperlinks to point to more specific parts (fragments) in the XML document.

For more information on XLink, please look at our XLink Reference.

Now You Know XLink, What's Next?

The next step is to learn about XQuery.

XQuery

XQuery is about querying XML data.

XQuery is designed to query anything that can appear as XML, including databases.

If you want to learn more about XQuery, please visit our XQuery tutorial.