Multitasking

Multitasking is the ability to handle more than one task at a time or to switch quickly between tasks. In everyday use, it describes managing several activities such as checking email while attending a meeting. In computing, multitasking refers to an operating system's ability to run multiple processes or threads, giving the appearance of parallel work.

Human multitasking is not true parallel processing. The brain typically handles tasks serially and spends time switching attention. Switches incur costs: longer completion times, more errors, and reduced learning efficiency. The size of the costs depends on task similarity, complexity, fatigue, and practice.

Research shows performance declines on complex, attention-demanding tasks when multitasking. Simple, well-practiced tasks may suffer less, especially with routines or external aids. People often overestimate their multitasking ability and underestimate its impact on accuracy and memory.

In computing, multitasking uses scheduling to run multiple tasks. Preemptive multitasking lets the OS interrupt tasks to maintain responsiveness; cooperative multitasking relies on tasks to yield control. Context switching lets the CPU switch between tasks; true parallelism is achieved on multi-core systems or with true concurrency in hardware.

Trade-offs exist: multitasking can boost efficiency for simple chores but may hinder performance on complex work. Strategies include reducing unnecessary switches, batching similar tasks, and using external aids to manage flow. In computing, hardware and software design determine the level of true parallelism and efficiency.