This book clearly explains the objectives of the integration of energy network, transportation network, information network, humanity network, as well as the integration of energy flow, information flow, material flow and value flow (4N4F); the philosophy, science, and engineering of the integration of 4N4F; the mechanism, keys and benefits of the integration of 4N4F; the carriers of the integration of 4N4F; and the framework of the integration of 4N4F.