The metric unit of mass is the "kilogram" (kg). The kilogram is the base unit for mass in the International System of Units (SI) and is widely used across the globe. One kilogram is defined as the mass of a specific platinum-iridium cylinder kept at the International Bureau of Weights and Measures. In everyday situations, the kilogram is commonly used to measure body weight, the mass of goods, and many scientific applications. It serves as the standard unit for mass measurement, facilitating consistency and accuracy in commerce, science, and engineering worldwide.