Friction is the force which opposes (resists) motion of the body. For example: If a block of wood is placed on a table it remains at rest Unless it is acted upon by an external force.The friction force has several advantages which includes the following:
1. It helps in walking process (because friction force stop us from slipping over).
2. It helps cars to move onroads easily due to friction between car tyres and road (makesa car stay on road) NOTE: Most car tyres have deep dreads to increase friction between the tyres and the road surface.
3. It helps in car braking system. Brakes rely on friction between the brake drum or pads and the wheels. In a bicycle, there are brake pads which clamp onto the wheel to slow it down.