The 120 volts or actually in the US the true voltage is 110, but most can be wired for either 110 or 220 which at 220 volts a motor runs more efficiently and is cost friendly

It used to be 110 volts, one leg of 220 volt wiring.  Today, we usually see 120 volts, one leg of 240 volt wiring.  110 to 130 volts is ok for a 120 motor.