Weight

"Heaviness". The downward force caused by gravity on an object.

The weight of an object can be different in different situations (such as in a moving elevator, or on the moon) while the mass stays the same.

This bar of gold has a mass of 1 kg, and weighing scales would normally show 1 kg (if they are here on Earth and not moving).

Weight uses the units of mass. For example grams, kilograms and, tonnes (Metric) or ounces and pounds (US units)