definitions—the root element of a WSDL contract. The attributes of this element specify the name of the WSDL contract, the contract’s target namespace, and the shorthand definitions for the namespaces referenced by the WSDL.

types—the XML Schema definitions for the data units that form the building blocks of the messages used by a service. For information about defining data types see Chapter 2, Defining Logical Data Units.

message—the description of the messages exchanged during invocation of a services operations. These elements define the arguments of the operations making up your service. For information on defining messages see Chapter 3, Defining Logical Messages Used by a Service.

portType—a collection of operation elements describing the logical interface of a service. For information about defining port types see Chapter 4, Defining Your Logical Interfaces.

operation—the description of an action performed by a service. Operations are defined by the messages passed between two endpoints when the operation is invoked. For information on defining operations see Operations.

binding—the concrete data format specification for an endpoint. A binding element defines how the abstract messages are mapped into the concrete data format used by an endpoint. This is where specifics such as parameter order and return values are specified.

service—a collection of related port elements. These elements are repositories for organizing endpoint definitions.

port—the endpoint defined by a binding and a physical address. These elements bring all of the abstract definitions together, combined with the definition of transport details, and define the physical endpoint on which a service is exposed.