Why is friction called self-adjusting force?

The force of friction (F^) increases with increase the applied force (F) till it is near the maximum value called limiting value of friction. The force of friction upto the maximum value is static friction because the body remains at the rest position till then with further increase in the applied force the frictional force decreases to become constant:. Thus value of frictional force is called dynamic friction or kinetic friction. Thus force of friction adjusts itself with applied force.