Abstract: An embodiment user awareness device includes a processor configured to receive first information about a first user from a first device, specify the first user based on a result of comparing the first information with pre-registration information, transmit data corresponding to a first service to the first device to provide the first user with the first service based on the pre-registration information, receive data on a history of the first service from the first device, receive second information about a second user from a second device, compare the first information with the second information to determine whether the second user is the first user, and transmit data corresponding to a second service associated with the first service to the second device to provide the second user with the second service in response to the second user being the first user.