Variable Timing. With synchronous communication, the caller must wait for the receiver to finish processing the call before the caller can receive the result and continue. In this way, the caller can make calls only as fast as the receiver can perform them. Asynchronous communication allows the sender to submit requests to the receiver at its own pace and the receiver to consume the requests at its own different pace. This allows both applications to run at maximum throughput and not waste time waiting on each other (at least until the receiver runs out of messages to process).
