Multitasking is the act of switching between two or more tasks, both of which are in the middle of executing. If one task is waiting, say for some input from the environment, the operating system will switch to executing another for the time being, thus ensuring that the computing resources are utilised judiciously, and progress happens.
Human adults are often needed to multitask. When the currently executing task stalls or waits for some reason and you can't do much about it except wait, a human often experiences emotions that an OS can't. There's impatience. Theirs anxiety. If the result of this task failing are bad or disastrous, these emotions are particularly strong.
A human may have to switch away from this stalled task since there are other tasks running and waiting for your attention. They may meet a sad fate if they don't get your attention while you can give it to them. Switching to other waiting tasks is but the most logical thing to do, because that's what an operating system would do. But this is also one of the hardest skills to learn because humans are not operating systems.
