What is the definition of mass in physical terms?

Mass, in physical terms, is defined as the quantity of matter within a body. This definition is fundamental in the study of physics, particularly in understanding concepts like weight, density, and inertia. Mass is a scalar quantity and does not change regardless of an object's location, meaning it remains constant whether an object is on Earth, the Moon, or in a vacuum.

Understanding mass is crucial because it directly relates to how objects respond to forces (as captured in Newton's second law of motion) and affects gravitational force. The larger the mass of an object, the greater the gravitational pull it exerts and experiences. This intrinsic property distinguishes it from external factors like force or motion, which are influenced by interactions with other objects and environmental conditions.