Phase or phases may refer to: In science In physicsPhase (matter), a physically distinctive form of a substance, such as the solid, liquid, and gaseous states of ordinary matterPhase transition is the transformation of a thermodynamic system from one phase to anotherPhase (waves), the initial angle of a sinusoidal function at its originPolyphase system, a means of distributing alternating current electric power in multiple conducting wires with definite phase offsetsSingle-phase electric powerT… (More on Phases)