A display apparatus is provided. The display apparatus includes a communication interface configured to communicate with a plurality of image input devices, a display configured to display a plurality of images provided by the plurality of image input devices on a single screen, a storage configured to store screen scale information of the plurality of image input devices, a sensor configured to sense a touch input on one image of the plurality of images, and a controller configured to convert actual touch coordinate values of an entire screen of the display into relative touch coordinate values corresponding to an image input device which provides a touched image in which the touch input is sensed, according to the screen scale information of the image input device which provides the touched image in response to the touch operation being sensed, and transmit the converted relative touch coordinate values to the image input device which provides the touched image.