Mass is a fundamental property of matter that quantifies the amount of substance in an object. It is often measured in units such as kilograms or grams. Mass is crucial in understanding how objects interact with each other through forces, as described by Newton's Laws of Motion. The greater the mass of an object, the more force is required to change its motion. In the realm of physics, mass is distinct from weight, which is the force exerted by gravity on an object. While mass remains constant regardless of location, weight can vary depending on the gravitational pull of a planet or moon. This distinction is important in fields like astronomy and engineering.