If we are using a spring type scale, or one of those digital things, we are actually measuring the gravitational pull on the object being 'weighed'.
We have learned that gravity changes in intensity depending upon where we are.
The further we are from the centre of Earth, for instance, the lower the effects of gravity will become.
In the not too distant future we will be wanting to make measurements, relevant to Earth, on the Moon, Mars or even Pluto,
As each of these places has a different gravity each of our measurements will simply be of weight in that specific environment.
The weight of an object will change according to the prevailing force of gravity which looks at the ammount of matter in an object.