XQuery, short for XML Query Language, is a World Wide Web Consortium (W3C) recommendation that provides the means to extract and manipulate data from XML documents or any collections of data that can be viewed as XML.
It's designed to be a straightforward way of querying XML data, whether it be a local XML document, a database of XML documents, or even live streams of XML data. XQuery includes XPath, and it adds a superset of XPath functionalities.
It is richly typed, and is capable of processing and constructing both the content and the structure of XML and other markup.