The unit of measurement for energy is the joule (J). A joule is defined as the amount of energy transferred when a force of one newton is applied over a distance of one meter. Other units for measuring energy include calories and kilowatt-hours, but the joule is the standard unit in the International System of Units (SI). Energy can manifest in various forms, such as kinetic, potential, thermal, and chemical energy. Understanding this unit helps in countless scientific applications, from physics to engineering.