What is electrical phase?

Three phase electric power systems carry unbalanced loads, currents, voltages or impedances in all the three phases that are usually 120 degrees offset in phase. The current and voltage signals do not peak at the same time and there is a phase difference depicted as a phasor diagram. The angle by which voltage leads current is denoted to represent the phase of the electrical signal. Using passive transformers, the load between the phases is balanced.