According to Wikipedia (www.wikipedia.com) a wiring diagram (also known as a circuit diagram, electrical diagram, elementary diagram, or electronic schematic) is,
“a simplified conventional pictorial representation of an electrical circuit. It shows the components of the circuit as simplified standard symbols, and the power and signal connections between the devices. Arrangement of the components interconnections on the diagram does not correspond to their physical locations in the finished device.”
While ConceptDraw.com, define wiring diagram as,
“a comprehensive diagram of each electrical circuit system showing all the connectors, wiring, terminal boards, signal connections (buses) between the devices and electrical or electronic components of the circuit. It also identifies the wires by wire numbers or color coding.”
Wiring diagram are necessary to troubleshoot and repair electrical or electronic circuits. For instance the wiring diagram for an automobile shows all the electrical components and that the interconnecting wiring is color coded. Thus make electrical troubleshooting easier.
Example of a Wiring Diagram
The above picture shows Honda CB350 Wiring Diagram. It describes the entire electrical system (components, interconnection, connectors) of the motorcycle.