>>2953632
https://www.allaboutcircuits.com/textbook/alternating-current/chpt-1/ac-phase/

The following values are not correct but are intended for illustration only.
DC is the same voltage all the time. (over a brief period) - A 12 volt battery stays at 12 volts.
AC is changing all the time. It goes to a peak level, back down to no volts, then peaks again in the opposite level. (0v, +12v, 0v, -12v, 0v, +12v, 0v, -12v)
Phases are when this occurs on multiple wires but the levels happen at different times.
phase one ^v^v^v^v^v^v^v^v^v^v
phase two v^v^v^v^v^v^v^v^v^v^

Earth (Ground) is a wire physically connected to the earth using a metal stake driven into the ground.
Neutral is considered the return path for the wiring in your home.
Line is the (source) path for the wiring in your home.

Properly wired, touching Neutral even when you are touching ground is safe.
Touching Line will result in a shock.