In this post, we will understand SOAP, WSDL and UDDI. Its important to know about these concepts before testing SOAP based webservices.

What is SOAP?

SOAP an XML-based protocol designed to provide the necessary infrastructure and definition to support XML based Remote Procedure Calls(RPC’s). It provides an envelope for encapsulating a message. Also, this envelope is an encoded message provided to an application server. Furthermore, an envelope typically wraps not only the method request, but also the request parameters.

The protocol provides  a set of well-defined data and parameter encoding rules. A common set of data-encoding rules is required for communication between service provider and consumer. Also, It provides a set of rules for describing the methods. In addition, this is required to make sure that both the service consumer and the service provider  of information understands and agrees on what the call means. A sample high level picture of SOA Architecture shown in below picture.

What is WSDL?

WSDL ( Web Service Description Language )  is how the Web service is described to the outside world. It defines an XML grammar for describing services and serves as a recipe for automating the details in application communication. WSDL describes a service’s methods, data inputs/outputs, and contact mechanism.

What is UDDI?

UDDI( Universal Description, Discovery, and Integration ) provides a mechanism for Web services providers to publish new and updated Web services and a mechanism for service consumer to find and access published Web services. UDDI enables businesses to publish and advertise the services they offer and describe how these services should be used.