Normal Contact Force

The normal contact force (also called the reaction force or support force) acts perpendicular to the surface of contact.

On a horizontal surface with no other vertical forces, the normal force equals the object’s weight ($N = mg$). On an inclined surface, the normal force is less than the weight.

The normal force is a contact force. It adjusts automatically to balance whatever perpendicular force is applied to the surface, up to the limit the surface can withstand.