Web Services

If a web application not fully published only its functions or modules are published to the rest of the world, it is called web service. Web Services are interoperable i.e. the modules can be written in any language in any platform and it can be accessed in any platform. The Web Services uses Simple Object Access Protocol (SOAP) for message transmission

The concept of web service is very simple; it contains three main parts Provider, Registry and Requester. The Provider is the user who wants to publish the functions as web services. For this the provider provides the details of the module and the connection oriented details such as port number in Web Service Description Language (WSDL). And register it in the Universal Description Discovery and Integration (UDDI) registry. The Requester requests a web service by searching the UDDI registry; the registry provides WSDL information to the requester. With the help of the WSDL the requester then connect to the Provider and uses the service.