Force of friction refers to the resistance encountered when two surfaces slide against each other or attempt to slide against each other. It opposes motion and depends on factors such as roughness and normal force.
Related terms
Static friction: The force that opposes motion between two surfaces that are not moving relative to each other.
Kinetic friction: The force that opposes motion between two surfaces that are in contact and sliding against each other.
Coefficient of friction: A value that represents the interaction between two surfaces in terms of how much friction is present. It differs for static and kinetic friction.