web service orchestration

Web service orchestration is the direction of specific web service business processes by a central controller.  

The controller, which can also be a Web service, coordinates asynchronous interactions, flow control, business transaction management and business process monitoring.  Business process modeling notation (BPMN) is used to define a visual representation of the flow and business process execution language (BPEL) is used to write the code that executes the services. 

Service orchestration plays an important part in a service-oriented architecture (SOA). Web service orchestration can be contrasted with web service choreography, the execution of asynchronous tasks without a central coordinator. 

See also: cloud orchestrator, VMware Orchestrator, Microsoft System Center Orchestrator