Why is rolling friction less than sliding friction?

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Sliding or
kinetic friction is the result of force of interaction between the particles that make
up the two surfaces that are in contact when they move against each other. It is the
value of the force of friction after the bodies have started to move and is less than
the force of static friction. The force of kinetic friction is given by the formula
Fk*N, where N is the normal force and Fk is the coefficient of kinetic friction. Fk
usually has values around 0.3 .

Rolling friction is
considerably less than sliding friction as there is no work done against the body that
is rolling by the force of friction. For a body to start rolling a small amount of
friction is required at the point where it rests on the other surface, else it would
slide instead of roll. This is provided by the static friction between a small part that
is in contact with the surface it would roll on. The coefficient of rolling friction has
values in the range 0.02-0.06 .