An electronic device (101, 210, 310, 510, 610, 710, 810, 910, 1010, 1110) comprising: a display (160, 230); and a processor, wherein the processor is configured to: display at least a first window and a second window in a display region of the display (160, 230), the display region corresponding to the part of the display that is exposed to the outside, and the size of the display region may be changed; identify a position of a user input (340-2, 340-3, 350-2, 350-3, 370-2, 370-3, 524, 534, 544, 645, 945, 950, 960, 1045, 1050, 1125); receive an input related to a size change of the display region of the display (160, 230); and change a size of the display region of the display (160, 230) and display a window corresponding to the identified position of the user input (340-2, 340-3, 350-2, 350-3, 370-2, 370-3, 524, 534, 544, 645, 945, 950, 960, 1045, 1050, 1125) in the display region of the display (160, 230); characterized in that the processor is further configured to: receive a notification message and display the notification message in the display region; receive a user input for extending the display region of the display at a position at which the notification message is displayed; in response to receiving the user input and based on the identified position of the user input, extend the display region, and execute an application related to the notification message to be displayed in the extended display region of the display. a display (160, 230); and a processor, wherein the processor is configured to: display at least a first window and a second window in a display region of the display (160, 230), the display region corresponding to the part of the display that is exposed to the outside, and the size of the display region may be changed; identify a position of a user input (340-2, 340-3, 350-2, 350-3, 370-2, 370-3, 524, 534, 544, 645, 945, 950, 960, 1045, 1050, 1125); receive an input related to a size change of the display region of the display (160, 230); and change a size of the display region of the display (160, 230) and display a window corresponding to the identified position of the user input (340-2, 340-3, 350-2, 350-3, 370-2, 370-3, 524, 534, 544, 645, 945, 950, 960, 1045, 1050, 1125) in the display region of the display (160, 230); characterized in that the processor is further configured to: receive a notification message and display the notification message in the display region; receive a user input for extending the display region of the display at a position at which the notification message is displayed; in response to receiving the user input and based on the identified position of the user input, extend the display region, and execute an application related to the notification message to be displayed in the extended display region of the display. display at least a first window and a second window in a display region of the display (160, 230), the display region corresponding to the part of the display that is exposed to the outside, and the size of the display region may be changed; identify a position of a user input (340-2, 340-3, 350-2, 350-3, 370-2, 370-3, 524, 534, 544, 645, 945, 950, 960, 1045, 1050, 1125); receive an input related to a size change of the display region of the display (160, 230); and change a size of the display region of the display (160, 230) and display a window corresponding to the identified position of the user input (340-2, 340-3, 350-2, 350-3, 370-2, 370-3, 524, 534, 544, 645, 945, 950, 960, 1045, 1050, 1125) in the display region of the display (160, 230); characterized in that the processor is further configured to: receive a notification message and display the notification message in the display region; receive a user input for extending the display region of the display at a position at which the notification message is displayed; in response to receiving the user input and based on the identified position of the user input, extend the display region, and execute an application related to the notification message to be displayed in the extended display region of the display. receive a notification message and display the notification message in the display region; receive a user input for extending the display region of the display at a position at which the notification message is displayed; in response to receiving the user input and based on the identified position of the user input, extend the display region, and execute an application related to the notification message to be displayed in the extended display region of the display.