W3C states: XSL is a language for expressing stylesheets. It consists of three parts: * XSL Transformations (XSLT): a language for transforming XML documents * The XML Path Language (XPath): an expression language used by XSLT to access or refer to parts of an XML document. * An XML vocabulary for specifying formatting semantics (XSL Formatting Objects) Informally, abbreviation "XSL" often refers to XSLT only, since the latter is in wider use. Also informally �XSLT� often refers to both �XSLT itself� and �XPath�, since most of XSLT document use XPath expressions.