Three ways to call an integrated service: Request Response, Run a Job and Wait for a Callback with Task Token.
Here, they are named as FIRE_AND_FORGET, SYNC and WAIT_FOR_TASK_TOKEN respectly.
Call a service and progress to the next state immediately after the API call completes.
Call a service and wait for a job to complete.
Call a service with a task token and wait until that token is returned by SendTaskSuccess/SendTaskFailure with paylaod.