Mass and Weight
We often use "weight" to mean "mass", and vice
versa. The mass of an object is often referred to as
its weight though these are in fact different
concepts and quantities.
Mass refers to the amount of matte in an object ,
whereas weight refers to the force experienced by
an object due to gravity.
Example: Out in pace mass stays the same weight
does not. The force of gravity on the Moon is only
one sixth of what it is on the Earth.