A display device includes a display; a first external interface configured to be connected to a first external device; a second external interface configured to be connected to a second external device; and a controller configured to display, on the display, an external source list menu including first connection port information for identifying the first external interface and second connection port information for identifying the second external interface and detect a connection signal indicating whether any one of the first external device or the second external device is connected to any one of the first external interface or the second external interface, wherein the connection signal includes at least one of a first connection signal indicating the first external device is connected to the first external interface or a second connection signal indicating the second external device is connected to the second external interface.