A lighting control system is an integrated solution that manages lighting across a building, including dimming, switching, occupancy sensing, daylight harvesting, scheduling, and central monitoring. Components include a central controller/gateway, dimmable LED drivers, sensors (occupancy, daylight), wall stations, and software. You likely need one if: your building is large (offices, hospitals, warehouses); you need to comply with energy codes (ASHRAE 90.1, IECC, Title 24) that mandate automatic shutoff and daylight responsiveness; you want to reduce energy costs (typically 30-60% savings); or you need flexible lighting scenes for different uses. For small spaces with simple on/off needs, basic switches or timers may suffice. Modern wireless systems (DALI-2, Zigbee, Bluetooth Mesh) have reduced installation costs, making control systems viable for smaller projects as well.