Mass is the amount of matter or the inertia of an object. Inertia is the object's resistance to motion. This is measured with a beam balance.
Weight is the force it exerts on anything that freely supports it. This is measured with a spring balance.
the mass of an object is constant anywhere in the universe while the weight is subject to change from place to place due to differences in g (acceleration due to gravity).
Weight is a force and is therefore measured in Newtons (N).
Weight = mass x gravitational field strength
W = mG
G has a value of 10 N/kg. It has the same value as the acceleration due to gravity, g, but have different units. g = 10m/s2. Alternatively the weight equation can be re-written as W = mg.