Kilowatt-hour (kWh) is a unit of energy. It is commonly used to measure electricity consumption. One kilowatt-hour represents the amount of energy used by a device that consumes 1 kilowatt of power continuously for one hour.
The formula to calculate energy in kilowatt-hours is:
\[
\text{Energy (kWh)} = \text{Power (kW)} \times \text{Time (hours)}
\]
Thus, kilowatt-hour is a unit of energy, not power, voltage, or electric current.