Compare and contrast weight and mass?

Mass is the an object's resistance to a change in inertia. This is why, and I have no personal experience with this, large objects in space or the free fall of orbit are hard to move.

Weight is the measured mass of an object multiplied by the acceleration due to gravity.

1 Newton = 1 Kilogram * 9.8 m/s^2

Weight = mass * acceleration due to gravity