A service control is a proxy for a web service. The web service client uses this proxy to access the web service. Using a service control allows the web service client to access the operations of a web service through simple method calls to the service control. A service control makes it easy to access an external web service from a Workshop client application. You can create a service control for any web service that publishes a WSDL file.
Note: You should not use a service control to invoke a web service that resides in the same application. Invoking a web service via a service control means marshalling the method parameters into a SOAP message on the calling end and unmarshalling the SOAP message on the receiving end, then again for the method return value. This is very inefficient when the invocation is local.