kWh

Meaning:

A kilowatt-hour (kWh) is a unit of energy. It measures the total amount of energy used over a period of time. One kilowatt-hour is the amount of energy consumed by a 1 kW device running for one hour.

For example, if you run a 1 kW appliance for 1 hour, it consumes 1 kWh of energy. Similarly, a 2 kW heater running for 3 hours will consume 6 kWh of energy (2 kW * 3 hours = 6 kWh).