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.