(XML PATH) A sublanguage in an XSL style sheet that is used to identify XML elements for processing. It is also used to calculate numbers and manipulate strings. XPath and XSLT expressions are intertwined. For example, although XPath can reference a variable, the variable must be created and given a value in XSLT. XPath syntax is somewhat like the directory addressing in Unix, which uses a slash for the root directory as well as the separator between hierarchies. See XSL and XQuery.