Kilograms VS Newtons
The measurement we use to define our weight (kilograms or pounds) is in effect the unit of measure of mass. Mass is measured in Kilograms, and it never varies: a body of mass 80kg will be the same on planet Earth as well as on the Moon or out in space. Mass is mass!
Newtons measure the force pulling a body towards a heavier body. We are attracted towards the center planet Earth. An object of one kilogram is attracted to the center of the Earth with a force of 9.8 Newtons. If you will take that same object to the Moon its mass will be just the same, but its weight will be much less.
Newtons are often rounded to facilitate calculations, and thus 1 kg is said to correspond to 10 Newtons. 10 Newtons make a Deca-Newton (daN) and 1000 Newtons make a Kilo-Newton (kN).