Display device and operation method thereof

A display device comprising:

• a display;
• a communication interface, comprising circuitry, configured to communicate with at least one of a first control device comprising a first key for executing a first function of the display device and a second control device comprising a second key for executing the first function of the display device;
• and
• at least one processor, comprising processing circuitry, individually and/or collectively configured to execute at least one instruction to cause the display device to:
• in response to a control signal corresponding to the first key being received from the first control device while first content is being played, perform a first operation to output a first full screen, and
• in response to a control signal corresponding to the second key being received from the second control device while the first content is being played, perform a second operation different from the first operation to output a second full screen different from the first full screen,
• wherein the first content comprises game content, and
• the first control device comprises a game control device having at least one key for exclusively performing a specific function related to the game content,
• wherein the at least one key comprises at least one of a game start key, a game end key, a game pause key, a game configuration key, a direction key, a position movement key, a vibration intensity control key, or a joystick.