Or the difference between the manager’s schedule and the maker’s schedule.
It may also help folks if they learn what really happens in 'multi-tasking' situations, when there is a single core, with a single CPU, and no majikal place to majikally offload concurrently running threads.
Ah yes, once upon a time the notion of 'thrashing the system' was reasonably well known.( would this be a bad time to point out that Silly Window Syndrome was never that Funny an idea or metaphour! )