The measure of the amount of matter in an object is referred to as mass. Mass is a fundamental property of matter and is usually measured in units such as grams (g) or kilograms (kg). It is distinct from weight, which is the force exerted by gravity on that mass. Mass remains constant regardless of location, while weight varies based on gravitational pull. Understanding mass is important in various scientific fields, including physics, chemistry, and engineering, as it influences how objects behave under different forces.