Being an XML document, the WSDL document uses elements to describe the web services. The root element of a WSDL document is definitions.
In the syntax for the definitions element, definitionName is the name of the WSDL document and NamespaceURI is the value for the targetNamespace attribute. NamespaceURI specifies the namespace for the names declared within the definitions element. The default namespace is as displayed in the syntax.
In the code example, SchoolLibrary is the name of the WSDL document and the corresponding namespace is displayed in the code.