WSDL Elements

Element Definition
<definitions> The root element contains name space definitions.
<portType> The most important WSDL element. It is a set of all operations that a web service can accept and is a container for <operation> elements. This WSDL element describes a web service, the operations that can be performed, and the messages that are involved, and can be compared to a function library (or a module or a class) in a traditional programming language.
<types> Defines variable types used in the web service (both the parameters passed to a function and the type of the value passed back via the response). The data types are described by XML schema. This element contains user-defined data types (in the form of XML schema). For maximum platform neutrality, WSDL uses XML schema syntax to define data types.
<message> Defines the data elements of an operation. Each message can consist of one or more parts that can be compared to the parameters of a function call in a traditional programming language.
<operation> Child of the <binding> element that defines each operation that the port exposes. This element allows three messages only:

Message - Definition

Input Message - Data web services receive

Output Message - Data web services send

Fault Message - Error messages from web services

<service> Contains a <port> child element that describes the URL where the service is located. This is the location of the ultimate web service.
<binding> Defines the message format and protocol details for each port. The binding element has two attributes: the name attribute and the type attribute. This element specifies how the client and the web service should send messages to one another.
Note: For more information about the WSDL standard, refer to the World Wide Web Consortium (W3C) Website at w3.org/TR/wsdl.