The standard unit of measurement for energy is the joule (J). A joule is defined as the amount of energy transferred when one newton of force is applied over a distance of one meter. The joule is a versatile unit and can be used to express various forms of energy, including kinetic, potential, thermal, and electrical energy. In practical terms, one joule is approximately equivalent to the energy released by a small battery. Other energy units, such as calories and kilowatt-hours, can also be converted to joules, making it a fundamental measure in physics and engineering.