Things you should know before working on Workflow.
*** A workflow built on Windows Workflow Foundation is a component that requires an ad hoc runtime environment to function. The workflow runtime environment is represented by the WorkflowRuntime class. To host a workflow library, you create and configure an instance of the WorkflowRuntime class to operate on a particular workflow type. For performance reasons, you normally create the runtime environment only once in the application lifetime and make it serve all incoming requests. In a Windows Forms application, you initialize the workflow runtime in the form's constructor and destroy it with the form when the application shuts down.