Kinetic friction is the force that resists the movement of two surfaces that are in contact with each other. It is caused by the microscopic bumps and grooves on the surfaces rubbing against each other.
The magnitude of kinetic friction depends on the nature of the surfaces in contact, the force pressing the surfaces together, and the relative speed between the surfaces.
Static friction is the force that resists the movement between two surfaces that are not moving relative to each other. It is greater than kinetic friction, which only occurs when the surfaces are in motion.
Kinetic friction cannot be completely eliminated, but it can be reduced by using lubricants or smoother surfaces. However, some amount of kinetic friction will always be present in any type of movement.
Kinetic friction is used in brakes of vehicles to slow them down, in sanding and polishing surfaces, and in sports like ice skating and skiing where friction is controlled to achieve desired movements.