Building Wire is a fundamental category of electrical wiring used primarily within buildings for both residential and commercial applications. This type of wire is designed to carry electrical currents to all power-using equipment including outlets, switches, and fixtures. Building wires must adhere to strict regulations concerning fire resistance, conductivity, and durability to ensure safety and efficiency. Common types include THHN, XHHW, and USE cables, each with unique properties like temperature resistance or suitability for wet conditions. Copper is predominantly used due to its excellent electrical conductivity, though aluminum options are available for larger installations where weight and cost are considerations. This category covers a range of wires designed to meet the electrical needs and safety standards of any building infrastructure.