An ounce is a unit of measurement used to quantify weight or mass, commonly employed in the United States and a few other countries that have not adopted the metric system. It measures the heaviness of objects or the mass of substances, particularly in culinary, commercial, and everyday applications. The symbol for ounce is "oz." In the avoirdupois system, which is standard in the United States, one ounce is equal to 1/16 of a pound or approximately 28.35 grams. The ounce is also used in the troy system for measuring precious metals like gold and silver, where one troy ounce equals approximately 31.10 grams. The ounce's widespread use in recipes, packaging, and trade underscores its practical importance, while its role in scientific and industrial applications highlights its utility in precise measurements, making it a versatile and enduring unit of measurement.