An outdoor electrical distribution box serves as the critical junction point where incoming power lines are split into multiple branch circuits for outdoor installations, parking lots, building exteriors, and industrial facilities. What is a Distribution Box? A distribution box, or DB box, is a circuit breaker enclosure. It is a vital part and central hub of any electrical system. It is usually installed on the wall or ground of a building and contains various major components and functions inside to ensure the safe, stable and efficient operation of the power. Distribution boxes come in various types, classified by their installation method, material, and function.