A wire is a conductor, a material that conducts electricity. In the case of home wiring, the conductors are copper or aluminum (or copper-sheathed aluminum), and are solid metal conductors or stranded wires.
The most typical type of wiring in modern homes is non-metallic (NM) cable, which consists of two or more individual wires wrapped in a shielded plastic jacket. NM cables typically consist of one or more "hot" (current-carrying) wires, a neutral wire, and a ground wire.
Underground Feeder (UF) is a non-metallic cable designed for wet locations and direct underground burial. It is often used to provide outdoor fixtures such as lamp posts.
THHN and THWN wires are single conductors with individual color-coded insulation. These wires are not shielded by the NM cable jacket, but by tubular metal or plastic conduit.
Conduit is commonly used in unfinished areas, such as cellars and garages, and for quick exposed pipes in houses, such as wiring connections for garbage disposals and water heaters.
Low-voltage wiring is used for circuits that typically require 50 volts or less. Several standard types are terrain lighting wires, sprinkler system connections, bell wires, speaker system wires, and thermostat wires.
A coaxial cable is a round shielded cable whose inner conductor is surrounded by a tubular insulating layer and covered by a tubular conductive shield made of braided wire. Coaxial cable was once the benchmark for connecting TVs to antennas or cable service delivery, and is still often used to connect satellite dishes or to bring subscription TV services to home distribution points.
