A smart controlling device for processing data according to a voice recognized using artificial intelligence, comprising: a receiver configured to receive a first voice input comprising a command trigger; a signal outputting unit configured to transmit a control command associated with an external display device; and a controller configured to: obtain a first location of a speaker of the first voice input based on the received first voice input; detect at least two external display devices within a predetermined range on the basis of the detected first location of the speaker; select a display device from the detected at least two external display devices based on the obtained first location of the speaker; cause a power status of the selected display device to be changed to a first state; and cause a response data corresponding to a first command data received after the command trigger to be output on a display of the selected display device wherein the controller is further configured to: detect the power status of the display of the selected display device; and when the power status of the display of the selected display device corresponds to a power-off status, cause the signal outputting unit to transmit a control command to change the power status of the display of the selected display device from the power-off status to a stand-by status. a receiver configured to receive a first voice input comprising a command trigger; a signal outputting unit configured to transmit a control command associated with an external display device; and a controller configured to: obtain a first location of a speaker of the first voice input based on the received first voice input; detect at least two external display devices within a predetermined range on the basis of the detected first location of the speaker; select a display device from the detected at least two external display devices based on the obtained first location of the speaker; cause a power status of the selected display device to be changed to a first state; and cause a response data corresponding to a first command data received after the command trigger to be output on a display of the selected display device obtain a first location of a speaker of the first voice input based on the received first voice input; detect at least two external display devices within a predetermined range on the basis of the detected first location of the speaker; select a display device from the detected at least two external display devices based on the obtained first location of the speaker; cause a power status of the selected display device to be changed to a first state; and cause a response data corresponding to a first command data received after the command trigger to be output on a display of the selected display device wherein the controller is further configured to: detect the power status of the display of the selected display device; and when the power status of the display of the selected display device corresponds to a power-off status, cause the signal outputting unit to transmit a control command to change the power status of the display of the selected display device from the power-off status to a stand-by status. detect the power status of the display of the selected display device; and when the power status of the display of the selected display device corresponds to a power-off status, cause the signal outputting unit to transmit a control command to change the power status of the display of the selected display device from the power-off status to a stand-by status.