2 Answers

Friction is the resistance offered to the movement of one material against another. It could be any two materials you can think of. Many of the jobs and activities we carry on in life would be impossible without friction.

Without friction, the belts of machines would slip, nails and screws wouldn’t hold, feet would not grip the floor or pavement, wheels would spin without making things move!

Yet in many cases, especially in machines, we actually try to reduce friction as much as possible. In the case of solid things, friction is caused mainly by unevenness in surfaces that touch each other. The smoother these surfaces, the less friction.

Interestingly enough, friction between unlike materials is less than that between substances of the same kind. When we lubricate the surfaces, as when we oil the bearings of machines, we reduce friction by substituting liquid friction for solid friction. Friction between solids is of two kinds—sliding and rolling.    

Talking about the friction, it is the simple phenomenon that arises when a body try to move on to another body surface.

For instance, when a ball is kicked, it stops after covering the distance.

The question that comes in mind at that instant, what thing make it to stop.

That force is nothing but friction.

In simple words, we can define the "Friction as the opposing force which opposes the motion of the body"

Note: This opposing force arises when a body try to move on to the surface of another body.

Hope you have understand the friction in simple. Now, you can share the same knowledge with your friends, too.