Energy is the capacity to do work. It exists in many forms, including heat, electrical, and chemical energy, and can be classified broadly as kinetic energy (energy of motion) or potential energy (stored energy). Although energy can be converted from one form to another, the total energy is always conserved.

能量是做功的能力。它以多种形式存在,包括热能、电能和化学能,并可大致分为动能(运动的能量)和势能(储存的能量)。能量虽可由一种形式转化为另一种,但总能量始终守恒。