Heya !!

Many people get confused between mass and weight. I'd like to state that they both are completely DIFFERENT things from one another. Let's see some points about each separately....

Mass.

1. Mass can be defined as the total quantity of mater contained by an object.
2. Mass is denoted by 'm' and is a scalar quantity.
3. The S.I. unit of Mass is KILOGRAMS (kg). Other units of mass are grams, pounds etc...
4. Mass of an object is constant everywhere in this UNIVERSE until and unless something is added to it or removed from it.

Weight.

1. Weight can be defined as the product of the mass of the object and acceleration due to gravity on a heavenly body. In other words, Weight is a force with which a heavenly body pulls an object.
2. Weight is denoted by 'w' and is a vector quantity.
3. Since Weight is a FORE, its S.I. unit is Newtons (N).
4. Since w = m * g, where w is weight, m is mass, and g is acceleration due to gravity, and the value of 'g' is not constant everywhere, the value of weight (w) is also not constant everywhere in this universe.

Hope it HELPS !!