The present invention may provide a display device that automatically configures a remote controller so that an external device connected to the display device can be controlled. According to the present display device, a power control code can be recognized on the basis of a response of a connected external device, and a control code set corresponding to the power control code can be received through a server. When there are a plurality of control code sets corresponding to the power control code, the corresponding control code sets can be received through the server by performing comparison with a user interface included in the video image received from the external device.