WSDL

This is an XML based language for describing web services.
This is used to describe the web service, the description of the methods provided (Web Service Description Language)
It specifies the location of the web service and the operations that is exposes

Different Component

A WSDL has several different components
definitions
types - the data types used by the web service should use XML schema syntax

message - the messages used by the web service

portType - the operations performed by the web service and the messages that are involved
There are four different types

One-Way - can receive a message
Request-Response - can receive a message and return a response
Solicit-Response - will send a request and wait for a response
Notification - can send a message and not wait for a response

binding - the communication protocols used. Defines the message format and protocol details
Binding to SOAP

binding element - this has two attributes (name - any name to describe the binding) (type - points to the port for the binding)
soap:binding element - this has two attributes (style - either "rpc" or "document") (transport - which SOAP protocol to use, typically http)
operation element - defines each operation

service - makes it possible to group several definitions together into a single WSDL document