Question

Phase epoch and phase difference

Answer 1

An phase epoch  means the beginning of a new phase.

In sinusoidal functions or in waves, "phase" has two different, but closely related, meanings. One is the initial angle of a sinusoidal function at its origin and is sometimes called phase offset or phase difference.

Answer 2

Phase epoch is the initial or the starting phase of a vibrating body where the time is equal to zero.

A phase difference is defined as the difference between the two sinusoids or phasors quantity having the same frequency with the same range of time. Phase differences are considered as the one-third of the cycle.