XPath is used to navigate through elements and attributes in an XML document.
XPath is a major element in W3C's XSLT standard - and XQuery and XPointer are both built on XPath expressions.
At W3Schools you will find a complete reference of all the built-in functions in XPath 2.0, XQuery 1.0 and XSLT 2.0.
This chapter explains what XPath is.
This chapter defines the different types of nodes in XPath and the relationship of nodes.
This chapter explains the XPath syntax.
This chapter explains the XPath axes.
This chapter lists the operators that can be used in XPath expressions.
This chapter uses the "books.xml" document to demonstrate some XPath examples.
This chapter contains a summary on what you have learned in this tutorial and a recommendation on what subject you should study next.