Frictional Force: The resistive force that opposes motion between two surfaces in contact with each other. It can act against or along with other forces to affect net force.
Normal Force:The perpendicular contact force exerted by a surface on an object resting on it. It counteracts gravitational pull and contributes to determining net force.
Applied Force:A push or pull exerted on an object by another object or person. Applied force can add to or subtract from other forces to determine net force.