XPath, short for XML Path Language, is a computing language that can select nodes or node-sets in an XML document defined by a variety of properties, such as location within the document, element type, attribute value, and more. XPath is a major element in the W3C's XSLT standard and can be used as a standalone language, or embedded in languages such as Javascript or PHP.
XPath gets its name from its use of a path notation as in URLs for navigating through the hierarchical structure of an XML document.
It provides basic facilities for manipulation of strings, numbers and booleans. XPath uses a non-XML syntax, which aims to provide more readability and usability than a pure XML syntax would.