What is the difference between aluminum foil facing and aluminum foil sheet?

Aluminum foil facing is a thin layer of aluminum laminated to a substrate, typically used in construction for insulation and moisture barrier purposes. It provides a reflective surface that can enhance energy efficiency by reflecting heat. On the other hand, aluminum foil sheet is a flat, flexible material made of pure aluminum or aluminum alloy, commonly used in cooking, food packaging, and crafts. It is not bonded to any other material and is available in various thicknesses and widths. The primary difference lies in their applications and composition; foil facing is part of a composite material for construction, while foil sheets are standalone materials for a variety of uses.