XSL Transformations (XSLT) uses XML Path (XPath) to access and refer to parts of an input document. XPath locates various document structures by representing those structures as node trees that can be navigated using location paths. The location paths have a very specific syntax that includes operators and expressions used to locate parts of a document according to the type of structure they represent. The seven basic structures that location paths allow you to access are
Root nodes Represent the root element in XML documents
Element nodes Represent all elements in XML documents, including root nodes
Attribute nodes Represent attributes in XML documents, including default and inherited attributes (but excluding ...