A closed circuit is a complete electrical loop that allows current to flow uninterrupted. In a closed circuit, all components, such as wires, batteries, and light bulbs, are connected in a way that enables electricity to travel from the power source to the load and back again. This flow of electricity is essential for devices to function properly. In contrast, an open circuit occurs when there is a break in the loop, preventing current from flowing. Closed circuits are commonly found in everyday items like flashlights and home electrical systems, where they power devices and appliances efficiently.