The voltage law, also known as Kirchhoff's Voltage Law (KVL), states that the sum of the electrical potential differences (voltages) around any closed loop in a circuit is equal to zero. This means that the total voltage supplied by sources, like batteries, must equal the total voltage drop across components, such as resistors, in that loop. In simpler terms, when you add up all the voltages in a circuit loop, the positive and negative values will cancel each other out. This principle helps engineers and electricians analyze and design electrical circuits effectively, ensuring that energy is conserved throughout the system.