What does a wiring diagram illustrate?

A wiring diagram provides a clear representation of the connections and layout of an electrical system. It typically includes symbols and lines that depict how different components are connected within the system, such as switches, outlets, and circuit breakers, as well as how power flows through these elements. This visual guide is crucial for electricians and technicians when troubleshooting or installing systems, as it allows them to understand the design and operational aspects of the electrical setup.

While other options discuss important aspects related to electrical work, they do not specifically address the primary purpose of a wiring diagram. Cost estimates pertain to budgeting and financial planning, architectural plans cover the overall structure of buildings, and safety protocols focus on ensuring that installations are conducted safely. Therefore, the third option specifically aligns with the function of a wiring diagram in illustrating the intricate connections and layout critical for an electrical system's functioning.