A system comprising a first terminal of a first user, a second terminal of a second user and at least one server, the system is configured to: access, by the first terminal, the at least one server using a first identifier of the first user; control, by the first terminal, a display of the first terminal to display information related to at least one registered Internet of Things, IoT, apparatus of the first user, wherein the information related to the at least one registered IoT apparatus of the first user is stored in the at least one server, wherein the first user has authorization to access and control the at least one registered IoT apparatus, receive, by the first terminal, through an input interface of the first terminal, an input for selecting an IoT apparatus of the at least one registered IoT apparatus based on the information related to the at least one registered IoT apparatus, control, by the first terminal, the display to display an authorization selection window for extending authorization of the IoT apparatus, the authorization selection window including a list of relationship groups associated with the first user, receive, by the first terminal, an input for selecting a relationship group in the list displayed through the authorization selection window for the IoT apparatus, control, by the first terminal, the display to display a group selection window for selecting a relationship group from the list of relationship groups for the second user, receive, by the first terminal, through the input interface an input for selecting a relationship group for the second user, and control, by the first terminal, a communication interface of the first terminal to transmit a request, for establishing relationship associated with the relationship group of the first user, to the second terminal, via the at least one server, in response to the input for selecting the relationship group through the group selection window, receive, by the at least one server, from the second terminal, an acceptance of the request, include, by the at least one server, the second user in the relationship group only when the second terminal accepts the request, grant, by the at least one server, access to the IoT apparatus to the second terminal based on the relationship established between the first user and the second user. access, by the first terminal, the at least one server using a first identifier of the first user; control, by the first terminal, a display of the first terminal to display information related to at least one registered Internet of Things, IoT, apparatus of the first user, wherein the information related to the at least one registered IoT apparatus of the first user is stored in the at least one server, wherein the first user has authorization to access and control the at least one registered IoT apparatus, receive, by the first terminal, through an input interface of the first terminal, an input for selecting an IoT apparatus of the at least one registered IoT apparatus based on the information related to the at least one registered IoT apparatus, control, by the first terminal, the display to display an authorization selection window for extending authorization of the IoT apparatus, the authorization selection window including a list of relationship groups associated with the first user, receive, by the first terminal, an input for selecting a relationship group in the list displayed through the authorization selection window for the IoT apparatus, control, by the first terminal, the display to display a group selection window for selecting a relationship group from the list of relationship groups for the second user, receive, by the first terminal, through the input interface an input for selecting a relationship group for the second user, and control, by the first terminal, a communication interface of the first terminal to transmit a request, for establishing relationship associated with the relationship group of the first user, to the second terminal, via the at least one server, in response to the input for selecting the relationship group through the group selection window, receive, by the at least one server, from the second terminal, an acceptance of the request, include, by the at least one server, the second user in the relationship group only when the second terminal accepts the request, grant, by the at least one server, access to the IoT apparatus to the second terminal based on the relationship established between the first user and the second user.