188.8.131.52. Synchronous vs. Asynchronous
A synchronous operation is a blocking operation as a process will wait until the operation completes. But an asynchronous operation is non-blocking as it only initiates the operation. An asynchronous operation allows more parallelism. Since the operation do not block the process, it can do some other computation while the operation is under progress.
A process flow is designed more as an asynchronous process and the submit from a process button will initiate the business process, but the form need not wait for the business process to complete.
A Microflow is designed as synchronous process as the system will wait for the data to be returned from a Microflow.