The Fanfpai ontology describes the resources (appliances) used in the Flexible Power Application Infrastructure (FPAI) . These resources are defined in the Resource Abstraction Interface (RAI class), which is used to express the energetic flexibility that appliances can offer and how this flexibility should be exploited. The RAI is an interface layer between: the Resource Abstraction Layer (RAL class) that monitors and controls the appliances and knows how much flexibility they can offer. The RAL consists of two main components: the resource manager (ResourceManager class) and the resource driver (not considered in this ontology); the energy apps (EnergyApp class) that are typically provided by a third party and exploit the flexibility that appliances have to offer. An energy app is only interested in exploiting energetic flexibility and not in the details of a specific appliance, such as a washing machine, for instance.