[fallous]

It's event driven in the manner of stimulus/response. A computer may process a series of instructions, but absent a loop it then finishes and does nothing without being told to process another series of instructions. Even within a listening loop it is essentially looking for "something to happen" and if nothing happens it NOPs, or does some basic house cleaning regarding the loop which is essentially the same. It is only when a stimulus occurs that the computer responds with a not-loop series of instructions.