A display system capable of displaying appropriate information on a controller that performs control on an industrial machine including at least a machine tool or a robot on an external terminal is provided. A numerical controller of a display system includes a display data transmitting unit that transmits display data including a screen data ID of all pieces of data displayed on a touch panel to an external terminal. The external terminal includes: a description information storage unit that stores the screen data ID and description information in correlation; and a description information output unit that acquires, from the description information storage unit, description information based on the screen data ID included in the display data received from the numerical controller and outputs the description information to a touch panel.