XSL stylesheet is just like a XML document used as a program text or a source. It contains sets of rules and instructions used for transformations. XSLT stylesheet along with the XML source documents are the inputs to the XSLT processor. The template rule contains two parts: a pattern used to match the nodes in the source document and a template which can be instantiated to form part of the result tree. A stylesheet is represented by an xsl:stylesheet element in an XML document.