Watt is a unit of power, within electrical systems wattage corresponds to the amount of power that an electric device uses per second.

Volt is a measurement of voltage, volts represent the electrical potential difference or pressure.

Ampere or amp is a measurement of electrical current, amps represent the rate at which electricity flows.
Volts/Watts/Amps Calculator is a type of calculator which is used to convert volt,amp to watt, watt,amp to volt and volt,watt to amps.
You can also get unit and you total bill in this app