Weight

What is weight?

The application of Newton's second law (Equation 60.1) in which $a$ is the acceleration of gravity:

$$F_{gravity} = mg$$ (61.3)

What is $F_{N}$?

The force that opposes the downward force of an object and is perpendicular to the plane in contact.

What is the relationship between $F_{N}$ and $F_{G}$?

Equal in magnitude, opposite in direction and acting on the same object.