A first terminal configured to operate in conjunction with a second terminal, the first terminal including: a sensor configured to obtain information corresponding to a motion of the first terminal; a communicator configured to receive information corresponding to a motion of the second terminal from the second terminal; and a controller configured to, in response to a distance between the first terminal and the second terminal being greater than or equal to a critical value, control the communicator to transmit a notification message to the second terminal based on the information corresponding to the motion of the first terminal and the information corresponding to the motion of the second terminal.