XPath is a language for selecting parts of an
XML document. While XPath is a full-fledged expression language which can be used for arithmetics, string functions and other evaluations, in most cases it is regarded as a way to select parts of an
XML document by selecting nodes which match certain criteria. XPath can be used as a stand-alone language, but in most cases it is embedded into host languages, the two most important host languages are
XSLT and
XSD.