Huawei Orange Huawei Telefonica Cisco Energy-efficient network management is primary meant to enhance conventional network management with energy-related management capabilities to optimize the overall energy consumption at the level of a network. To that aim, specific features and capabilities are required to control (and thus optimize) the energy use of involved network element and their components. This document is defines a set of key terms used within the IETF when discussing energy efficiency in network management. Such reference document helps framing discussion and agreeing upon a set of main concepts in this area.