A light emitting device (LED) array module includes at least one terminal, a light emitting device (LED) array, and a rank storing device. The LED array includes a plurality of LEDs that emit light when a current is supplied from the outside of the LED array module. The rank storing device is configured to store rank information of the LED array that depends on brightness characteristics of the LEDs, and to output a signal corresponding to the rank information via the at least one terminal.