The main switch, or main breaker, controls the entire electrical supply to the distribution box. Just as a heart receives blood and pumps it to various parts of the body, the distribution box receives the main electrical supply and. A distribution boxes acts as the load center and main distributor of electrical power within a building. It integrates power distribution, protection, and monitoring capabilities, and is responsible for distributing power to entire commercial or residential. Distribution boards, often referred to as electrical panels or breaker boxes, serve as the nerve center of any electrical system.