Friction; Conceptual questions about friction.

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Does kinetic friction depend on area? What about Normal force? or speed? And what is the difference between static and kinetic friction.
Please help me understand kinetic friction.

When two surfaces are in contact there molecules are close enough to exert intermolecular force which is electromagnetic force on each other. This force may be attractive or repulsive in nature depending on the distance between the molecules. Thus the force behaves as the force of a spring connecting two blocks. The distance between the molecules is less the force is repulsive and if the distance is more that a particular distance the will be attractive.
When a block is placed on a horizontal surface of a table, due to its weight the block have a tendency of accelerating downward. This compress the surface of the block and the table but as the molecules comes close there is a resultant repulsive force on each ...