LED lights can operate on either AC (alternating current) or DC (direct current), depending on their design and application. Most household LED bulbs you screw into standard light fixtures are AC-powered, since home electrical wiring typically delivers AC current at 120V (in North America) or 230V (in Europe). These bulbs contain an internal driver circuit that converts AC power to the DC power that LEDs require to function.
DC-powered LED lights are common in other settings: battery-operated flashlights and headlamps use DC from batteries, solar garden lights run on DC from batteries charged by solar panels, and automotive LED lights operate on the DC power from a vehicle's battery system. LED strips and modules used in decorative or industrial applications are frequently DC-powered, typically at 12V or 24V.
The key point is that LEDs themselves are semiconductor devices that inherently require DC current to emit light—they cannot directly use AC. When AC LEDs exist, they contain built-in rectification and conversion circuitry. So while the electrical source might be AC or DC, the actual LED diode always needs DC current flowing through it. The choice between AC and DC in practical applications depends on the power source available, the desired application, and efficiency considerations.