Connecting nodes is a lot like connecting the dots on a map. If two points on a map look close together, there is a good chance you will be able to connect two nodes placed at those points. However, there is an equally likely chance, that you won’t. In that case, you may need to find an intermediate point between your nodes, a point that both nodes can see. At length, there is an endless vareity ways of connecting any two nodes. But every network starts with just two nodes.
Maybe your network will grow so big that it can see another network. You could then build a bridge between the two networks, creating a larger network made up of smaller networks. Perhaps, one day, this theoretical creation will be called an INTER-NETwork.