A closed circuit is an electrical circuit that provides a complete path for electric current to flow. In a closed circuit, all components, such as wires, resistors, and power sources like batteries, are connected in a loop, allowing electricity to travel uninterrupted. This is essential for devices to function properly. In contrast, an open circuit has a break in the path, preventing current from flowing. Closed circuits are commonly found in everyday items like flashlights and light bulbs, where the flow of electricity is necessary for operation. Understanding closed circuits is fundamental in electronics and electrical engineering.