idling

Idling is the state of being inactive or not engaged in productive activity. It can refer to a person’s time between tasks, or to a system that is powered on but not currently executing work. Idling can be voluntary or involuntary and may serve several practical purposes or reflect inefficiency.

Engine idling occurs when an internal combustion engine runs while the vehicle or machine is stationary. Reasons include warming up, maintaining climate control, or waiting for a task to begin. While idling preserves readiness, it consumes fuel and produces emissions without performing useful work, and is often subject to regulation.

Computing and electronics also experience idling. A central processor or system can be idle when no tasks are scheduled, allowing it to enter low-power states to save energy. Idle time is a standard metric in performance analysis and resource management, balancing responsiveness with power use and wear on components.

Reducing unnecessary idling is a common goal in transport, industry, and data centers. Practices include stop-start systems and idle-time policies for vehicles, advanced power management, and scheduling that minimizes idle cycles. In some contexts, brief idling remains necessary for safety, comfort, or system maintenance.