vrms stands for “root-mean-square”.
This is an average voltage, not peak. This is used to determine how much energy is transferred from one point to another on a sinusoidal curve.
It’s worth mentioning that there are many forms of power measurement and conversion units in the technical world, including watts (heating), megawatts (industrial) and gigawatts (electricity). All three have different values when converted back into kilowatts (which we use at home).
A voltmeter measures volts alternating current – AC which fluctuates between low peaks and high peaks at certain rates per second. Ammeters measure amps DC flows of direct current which flow in one direction even during peak moments.