Electrical Components Belong To Circuits
All the electrical components in a vehicle are part of a circuit. Circuits are simply layouts, or designs, of how electrical components are powered and controlled. Electrical components found in automobiles are usually divided into categories of circuits, but this is not always the case. Some examples include a lighting circuit, a charging circuit, and a fuel injection circuit. Within each of these circuits are individual circuits that control specific electrical components. For example, headlights and tailights are part of the lighting system, but each operates on a separate circuit within that system.