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.
Kilotons (explosive energy)
A kiloton is a unit of measurement that quantifies the energy released in an explosion. It is the energy released by detonating 1,000 tons of TNT (trinitrotoluene). One kiloton is approximately equal to 4.184 × 1012 joules.