What is the purpose of declaring and defining the namespace in an XSLT stylesheet?

In an XSLT stylesheet, the purpose of declaring the XSLT namespace is to differentiate XSLT instructions (like < xsl:template > , < xsl:value-of > , etc.) from the elements in the source XML.

“XSLT uses XML syntax, so to avoid confusion with the actual data, all XSLT elements must be associated with the XSL namespace xmlns:xsl= " http://www.w3.org/1999/XSL/Transform " .”

This ensures the processor interprets < xsl:* > tags as transformation logic, not content.

Why others are incorrect:

A. XML version is declared separately ( < ?xml version= " 1.0 " ? > )

C. Encoding is set in the XML declaration, not in namespaces.

D. Namespaces are not used to retrieve external transformation rules.