A CPU governor is software that dynamically manages the power consumption and operating frequency of a computer's central processing unit (CPU). It adjusts the CPU speed based on system workload, aiming to optimize either performance or energy efficiency. Common in Linux-based systems, CPU governors use different policies, such as 'performance' for maximum speed or 'powersave' for reduced energy use. By switching between these modes, the governor helps balance computing power with battery life or thermal constraints, making it important for both servers and mobile devices. Proper configuration of CPU governors can enhance system responsiveness or extend device longevity.