parallel system tools "telling the monkeys what to domost computers spend lot of time doing nothing if you start system monitor tool and watch the cpu utilizationyou'll see what mean--it' rare to see one hit percenteven when you are running multiple programs there are just too many delays built into softwaredisk accessesnetwork trafficdatabase querieswaiting for users to click buttonand so on in factthe majority of modern cpu' capacity is often spent in an idle statefaster chips help speed up performance demand peaksbut much of their power can go largely unused early on in computingprogrammers realized that they could tap into such unused processing power by running more than one program at the same time by dividing the cpu' attention among set of tasksits capacity need not go to waste while any given task is waiting for an external event to occur the technique is usually called parallel processing (and sometimes "multiprocessingor even "multitasking"because many tasks seem to be performed at onceoverlapping and parallel in time it' at the heart of modern operating systemsand it gave rise to the notion of multiple-active-window computer interfaces we've all come to take for granted even within single programdividing processing into tasks that run in parallel can make the overall system fasterat least as measured by the clock on your wall just as important is that modern software systems are expected to be responsive to users regardless of the amount of work they must perform behind the scenes it' usually unacceptable for program to stall while busy carrying out request consider an email-browser user interfacefor examplewhen asked to fetch email from serverthe program must download text from server over network if you have enough email or slow enough internet linkthat step alone can take minutes to finish but while the to watch on windowsclick the start buttonselect all programs accessories system tools resource monitorand monitor cpu/processor usage (task manager' performance tab may give similar resultsthe graph rarely climbed above single-digit percentages on my laptop machine while writing this footnote (at least until typed while truepass in python interactive session window