Mass is a physical quantity. it is the quantity of matter present in a given body. it is measured in kg. weight is the product of mass and gravitational acceleration of the given situation. it is measured in newtons. 
Mass generally represents the ability of the body’s resistance to be accelerated by a force.  Between masses there will be gravitational force of attraction. It is measured by Kilogram only . But do not get confused with weight whose unit is also the same.  But mass is usually represented by M. Where as  weight  of  the object is the force on the body due to gravity. And is represented by W . For the sake of definition,  it is measured as the product of mass and its local acceleration due to gravity. So w= mg. Also measured in Kilograms usually but in physics you should measure in Newton.