The reaction force exerted by any surface on the body in contact is taken as apparent weight of the body.
The contact force exerted by a body A on another body B is equal to the normal force between the bodies. We conclude that(a) the surface must be frictionless(b) the force of friction between the bodies is zero(c) the magnitude of normal force equal that of friction(d) the bodies may be rough but they don't slip on each other.