Wave is one of the marine renewable energy sources with the greatest potential. Currently, the technology is not completely prepared for a commercial development and its levelized cost of energy (LCOE) is still high. In fact, there are numerous types of wave energy converters (WECs) in the development phase. Given the differences between them, there are several classifications based on different aspects such as the location in relation to the distance to the coast and the bathymetry, the position relative to the sea level, the size and orientation, and the energy capture principle. However, none of the existing classifications considers the operating range at rated power according to the power matrix of the devices. This paper includes a new proposal for classification of WECs, named OPERAWEC (Operation Waver Energy Converters), with the aim of covering that gap. A methodology to implement the classification to different WECs is proposed, and that methodology is applied to ten different existing WECs (Wave Dragon, Pelamis, Aquabuoy, Archimedes Wave Swing, Oyster, Oceantec, OE Buoy, Pontoon, Seabed AB and Wavebob), classifying them into six different groups (Group I, Group II, Group III, Group IV, Group V and Group VI). Most of them belong to the Group IV and/or Group V, and some of them are categorised into several groups. The paper ends showing how to apply OPERAWEC classification as a part of a screening process for WECs selection in the Spanish Atlantic coast. Wave resource is assessed in two specific locations (Estaca de Bares and Golfo de Cádiz), considering four WECs (Pelamis, Aquabuoy, Archimedes Wave Swing, and Oyster). According OPERAWEC classification, Group II WECs for Estaca de Bares, and Group I and Group II WECs for Golfo de Cádiz are recommended.