Call Orchestrations:
The Call Orchestration shape can be used to synchronously call an orchestration that is referenced in another project. This allows for reuse of common orchestration workflow patterns across BizTalk projects. When you invoke another nested orchestration synchronously with the Call Orchestration shape the enclosing orchestration waits for the nested orchestration to finish before continuing.
Start Orchestration
You use the this shape to invoke another orchestration—that is, the flow of control in the invoking orchestration proceeds beyond the invocation, without waiting for the invoked orchestration to finish its work.
