The xml prolog of a xml document is the beginning of an xml document. It consists of the information about the xml document and can be used by both the users and computers to know about the document. The prolog to an xml schema must contain:
XML declaration : The xml declaration is used to specify the version of xml used to write it and to declare that the document is an xml.
For Example:
<?xml version=”1.0” encoding=”UTF-8”?>
The xml element or root declaration : It defined the root element within which all the other xml elements / tags used are contained. In case of schemas it consists of an xmlns ( xml namespace) attribute that is used to define the namespace for the schema.
For Example:
<xsd:schema xmlns: xsd=”http://www.abc.org/2001/XMLSchema”>