The term mass and weight in English language are often used interchangeably. But in physics, they have completely two different meaning.

Mass:

• amount of matter in a physical body.

• scalar quantity (have magnitude only)

• base quantity (is not define in term of other quantities)

• SI unit: kilogram (kg)

Weight

• the force exerted on the mass of a body by a gravitational field.

• vector quantity (have both magnitude and direction)

• derived quantity (derived from mass and acceleration due to gravity, g)

• SI unit: newton (N)/ SI base unit: kilogram metre per second squared (kgms⁻²)