Friction is defined as the force that opposes motion when an object is sliding over a surface.
As a result of friction, all objects moving over a surface eventually come to rest over time.If we were to successfully create a friction-less surface, an object will remain in motion forever because it will encounter no opposition to its motion.
Hence, the resistance to the motion of objects over a surface which causes the objects to come to a halt after moving over the surface for some time is called friction.
