Most of the people think that mass and weight are the same things. The people who think that mass and weight are the same things are wrong. There is a big difference between mass and weight. The difference between mass and weight is given below;
1 1) Difference in the definitions of mass and weight

Mass and weight 
Mass
As we know that each body in the universe is made up of matter. In this way, the quantity of that matter in a specific body is called the mass of that body.
Weight
On the other hand, it is also a reality that Earth attracts everything towards its center with a force. That force is called the Gravitational Force. In this way, weight is the measurement of such force by which the Earth attracts a body towards its center.
2) Difference in the type of quantities
As we know that there are two types of quantities. One is the scalar quantity and the second is the vector quantity.
Mass
The mass of a body is a scalar quantity. A scalar quantity is such a quantity which is described only with the help of magnitude and there is no need of direction for its description. For example, 5kg sugar is a scalar quantity.
Weight
On the other hand, weight is a vector quantity. A vector quantity is such a quantity which is described by the magnitude as well as direction. The direction of the weight is always directed towards the center of the Earth. The simplest example of the vector quantity is the Force.
3) Difference in the nature of mass and weight
Mass
The nature of mass is that it remains constant everywhere.
Weight
On the other hand, the nature of weight is different from the mass. Its reason is that weight of a body doesn’t remain constant. It varies from one point to another point.
4)
Mass
The mass of a body can’t be zero.
Weight
On the other hand, the weight of a body can be zero. Its reason is that it depends upon the gravity and gravity can be zero and in this regard, the weight of a body can also be zero.
5) Difference in the formulas of mass and weight
Mass
We use two different formulas to determine the mass and weight of a body. When we are going to measure the mass of a body, then we use the following formula;
F=ma or m=F/a This formula is derived with the help of Newton’s second law of motion.
Weight
On the other hand, when we are going to measure the weight of a body, then we use the following formula;
W=mg
6) Difference in the measuring instruments of the mass and weight
Mass
If we want to measure the mass and weight of a body, then it is also necessary for us to use the two different measuring instruments. If we want to measure the mass of a body, then we use the ordinary balance.

Ordinary balance 
Weight
On the other hand, if we want to measure the weight of a body, then we use the spring balance.

Spring balance 
7) Difference in the SI units of the mass and weight
Mass
We use the two different SI units for the mass as well as for the weight. The SI unit for the mass is kg.
Weight
On the other hand, the SI unit for the weight is N.