Kilojoules
A kilojoule (kJ) is equivalent to one thousand joules (J). It is the energy required when a force of one thousand newtons is applied over a distance of one meter, or one newton applied over a kilometer. In reality, a joule is roughly the energy required to lift a small apple one meter against Earth's gravity.
Calories (20°C)
A Calorie (20°C) is sometimes referred to as a small calorie or gram calorie. It is a unit of energy defined as the amount of heat required to raise the temperature of one gram of water by one degree Celsius from 19.5°C to 20.5°C.