What does a kilowatt-hour measure?

Answer 1

It is a unit of energy. If energy is transferred at a rate (power) of one kilowatt, during one hour, then one kilowatt-hour (kilowatt times hour) of energy will be transferred. Since a joule is equal to a watt-second, a kilowatt-hour is the same as 3.6 million joules.

Answer 2

The "kilowatt hour" is a unit of energy.

It's the amount of energy used when energy is flowing at the rate of 1,000 watts for 1 hour.