The type of energy measured in joules is mechanical energy, which encompasses both kinetic and potential energy. Kinetic energy refers to the energy possessed by an object due to its motion, while potential energy is energy stored in an object based on its position or condition, such as an object lifted above the ground. The joule, named after the physicist James Prescott Joule, is the standard unit of energy in the International System of Units (SI). This measurement is fundamental in various fields, including physics, engineering, and thermodynamics, illustrating how energy is quantified and exchanged.