Electrical wire” is a catchall term that refers to conductors that route electricity from a power source to lights, appliances, and other electrical devices.

Wires and cables of various sizes bring electricity to a house and route it to all the lights, switches, receptacles, and electrical appliances. Generally speaking, large cables deliver electricity to the house and smaller cables and wires distribute it throughout.

Nearly all household wire is copper, though aluminum is occasionally used. A rubber, plastic, or paper-like coating, called insulation, serves as a barrier to keep the electrical charge (and heat) where it belongs—in the wire (this insulation is stripped from the ends of the wires where connections are made). Bare (non-insulated) conductors are used for grounding.

How Electrical Wiring Works

Wire is a comprehensive term commonly used to refer to all types of cable and wire. Technically, an individual wire is called a single conductor; several single conductors twisted together or combined together in a sheath make a cable.

Just as highways can handle more cars than small streets, large conductors can handle more electricity than small ones. The diameter of a metal conductor is indicated by an AWG (American Wire Gauge) number; the smaller the number, the larger the wire. Most household lighting and receptacle circuits are wired with AWG 14 or AWG 12 conductors.

In addition to standard electrical wire, a house has several other types of wire needed for the telephone, cable television, stereo speakers, and so on. Most of these wires do not carry a dangerous electrical current because they operate on very low voltage or carry only sound or picture signals, not electrical power.