(1) The CPU is like the brain. Based on sensory input, the human brain acts on conscious thought while a human is awake, similar to how a waiter or waitress waits on people and continually asks them if they need anything.

(2) The main memory is like our waking consciousness - what we are thinking right now. Someone copying data (e.g. written notes) from one place to another may store it briefly in his or her brain’s short-term memory during the copy process as he or she looks away from the source to the place where she or he is copying the data.

(3) The secondary memory is like our long-term memory. A student stores information away in his or her long-term memory while studying material in order to recall it later for quizzes, even after sleeping.

(4) Input devices are like our 5 senses.

(5) Output devices are like our facial expressions, gestures, or speech.