The avoirdupois pound is a unit of weight commonly used in the United States and other countries that follow the imperial system. It is defined as exactly 0.45359237 kilograms. The term "avoirdupois" comes from Middle French, meaning "goods of weight," and it was historically used for trade and commerce. This pound is part of the avoirdupois system, which includes other units like ounces and tons. Unlike the troy pound, which is used for precious metals, the avoirdupois pound is the standard for most everyday goods, making it essential for cooking, shipping, and various industries.