Friction is generated when interact with each other on sliding surfaces.

Friction is generated when molecules interact with each other on sliding surfaces.

Explanation:

As we know that friction force is the contact force between two surfaces. When two surface are placed over each other then in that case molecules of one surface are in contact with the molecules of other surface.

Due to the close interaction all the molecules will form a weak attraction force which will make them bonded with each other.

Now due to this weak bond when we move one surface relative to other surface then we need the force to break the bond between two surface which is known as friction force.

So here we can say that

Friction is generated when molecules interact with each other on sliding surfaces.