A "slug," in the context of mass, is a unit of measurement primarily used in the United States customary and British imperial systems. It is not a widely used unit and is considered somewhat archaic. The slug is used to measure mass and is defined as the mass that accelerates at a rate of one foot per second squared (1 ft/s²) when a force of one pound-force (1 lbf) is applied to it. In other words, a slug is the mass that results in an acceleration of 1 ft/s² when a force of 1 lbf is applied to it.
The gram (g) is a unit of mass in the International System of Units (SI). It is one-thousandth of a kilogram, making it a smaller unit of mass.
To be more precise, one gram is equal to 0.001 kilograms, or 1 gram = 0.001 kg.
The gram is commonly used for measuring smaller masses, such as the weight of food items, small objects, or quantities of substances in scientific experiments or in everyday life. It provides a more convenient and manageable unit for expressing masses that are not as large as those typically measured in kilograms.