Ma'anar ƙamus na kalmar "lantarki" yana nufin adadin lokacin da ake canjawa wuri ko cinye makamashin lantarki a cikin lantarki. Yana da adadin kuzari a kowane lokaci naúrar, yawanci ana aunawa a watts (W), kilowatts (kW), ko megawatts (MW). Wutar lantarki shine samfurin ƙarfin lantarki da na yanzu a cikin da'irar lantarki, wanda aka bayyana ta lissafi azaman P = VI, inda P yake wuta, V shine ƙarfin lantarki, ni kuma na yanzu. Ana amfani da wutar lantarki don sarrafa na'urori da tsarin da ke buƙatar wutar lantarki, kamar na'urori, fitilu, da injinan masana'antu.