In electricity, a phase is a voltage or current that exists between an active wire and a neutral cable. An oscilloscope, a digital device that plots a graph of the instantaneous signal voltage as a function of time, is used to evaluate the waveform of the electronic signals it is producing.
Additionally, whether a phase is a single-phase or three-phase, its power relies on how its electric load is distributed according to the type of unit.
A single-phase (1 phase) system uses two wires and produces less power than a three-phase (3 phase) system, which uses three or four wires and produces more power.
Source: https://pocketsparky.com/knowledgebase/three-phase-power-what-is-3-phase/