A display device (100, 400, 600, 700), comprising: a display; a speaker; a communicator comprising communication circuitry configured to perform wireless communication; a memory configured to store one or more instructions; and a controller comprising at least one processor configured to execute at least one of the one or more instructions, wherein, the communicator is further configured to: in response to a wireless connection request being received from an external device, wherein the wireless connection request is for transmission of audio from the external device for output by the display device (100, 400, 600, 700), while the controller is in a first power state in which the display is in a screen-off state, transmit, to the external device, a response indicating acceptance of the wireless connection request to establish a first wireless connection with the external device, transmit, to the controller, information associated with the external device, and control the controller to switch a power state from the first power state to a second power state, in response to switching the power state of the controller from the first power state to the second power state, disconnect the first wireless connection with the external device, and the controller is further configured to: control the communicator to establish a second wireless connection with the external device using the information associated with the external device. a display; a speaker; a communicator comprising communication circuitry configured to perform wireless communication; a memory configured to store one or more instructions; and a controller comprising at least one processor configured to execute at least one of the one or more instructions, wherein, the communicator is further configured to: in response to a wireless connection request being received from an external device, wherein the wireless connection request is for transmission of audio from the external device for output by the display device (100, 400, 600, 700), while the controller is in a first power state in which the display is in a screen-off state, transmit, to the external device, a response indicating acceptance of the wireless connection request to establish a first wireless connection with the external device, transmit, to the controller, information associated with the external device, and control the controller to switch a power state from the first power state to a second power state, in response to switching the power state of the controller from the first power state to the second power state, disconnect the first wireless connection with the external device, and the controller is further configured to: control the communicator to establish a second wireless connection with the external device using the information associated with the external device. in response to a wireless connection request being received from an external device, wherein the wireless connection request is for transmission of audio from the external device for output by the display device (100, 400, 600, 700), while the controller is in a first power state in which the display is in a screen-off state, transmit, to the external device, a response indicating acceptance of the wireless connection request to establish a first wireless connection with the external device, transmit, to the controller, information associated with the external device, and control the controller to switch a power state from the first power state to a second power state, in response to switching the power state of the controller from the first power state to the second power state, disconnect the first wireless connection with the external device, and the controller is further configured to: control the communicator to establish a second wireless connection with the external device using the information associated with the external device.