is kwh a unit of power or work?
A kilowatt hour (kWh) is a measure of energy. So a 1,000 watt drill needs 1,000 watts (1 kW) of power to make it work, and uses 1 kWh of energy in an hour. That's why, if you leave a TV or computer on standby, it is still using power and creating a kWh cost on your energy bill.