A display apparatus and a controlling method are provided. The display apparatus includes a communication interface configured to receive a plurality of image signals from a plurality of external devices, a display configured to display a screen including a plurality of regions respectively corresponding to each of the plurality of image signals, and a processor configured to, in response to a directional touch gesture being input on the display, select a region from among the plurality of regions based on a direction of a directional touch gesture and control the display to display the selected region as a full screen.