XLink defines a standard way of creating hyperlinks in XML documents.
XPointer allows the hyperlinks to point to more specific parts in the XML document.
XLinkIn HTML, we know (and all the browsers know!) that the "a" element defines a hyperlink. However, this is not how it works with XML. In XML documents, you can use whatever element names you want - therefore it is impossible for browsers to predict what hyperlink elements will be called in XML documents.
To get access to the XLink attributes and features we must declare the XLink namespace at the top of the document.
XPointerIf the hyperlink points to an XML document, we can add an XPointer part after the URL in the xlink:href attribute, to navigate (with an XPath expression) to a specific place in the document.