<Li> It can refer to φ (\ displaystyle \ scriptstyle \ varphi \,), in which case we would say x (t) (\ displaystyle \ scriptstyle x (t) \,) and y (t) (\ displaystyle \ scriptstyle y (t) \,) have the same phase but are relative to their own specific references . </Li> <Li> In the context of communication waveforms, the time - variant angle 2 π f t + φ (\ displaystyle \ scriptstyle 2 \ pi ft \, + \, \ varphi), or its principal value, is referred to as instantaneous phase, often just phase . </Li>

Is a specific time point in a wave’s cycle