Kilowatt-hours
A kilowatt-hour (kWh) is the amount of energy when a power of one kilowatt (1,000 watts) is used continuously for one hour. Utility companies often bill consumers based on the number of kilowatt-hours consumed.
Calories
A calorie is a unit of energy often used in nutrition to quantify the energy content in food. Specifically, one calorie (cal) is defined as the amount of energy required to raise the temperature of one gram of water by one degree Celsius at a pressure of one atmosphere.