An electrical panel, also called a service panel or load center, is the metal enclosure where utility power from the meter is divided into branch circuits. It holds the main breaker, which can shut off the whole house, and rows of circuit breakers, each sized to protect one circuit's wiring. Panels carry a UL listing and an amperage rating.
Why it matters to you
Every circuit in the house runs through the panel, so warning signs there, such as a burning smell, buzzing, scorched breakers, or a cover that is warm to the touch, affect the safety of the whole home.
Practical guidance
Keep the area in front of the panel clear, since NEC working-space rules generally call for about three feet of open space, and keep the circuit directory labeled. Never remove the inner cover yourself; if you smell burning or hear buzzing, switch off the main breaker only if it is safe to reach, then call an electrician.