Static friction is called self adjusting friction.
It is called so because the static friction adjusts itself to provide an equal and opposite force to the applied external force as long as the external force is less than or equal to the maximum static friction.
For example, Let the maximum static friction is 20N.
If we apply a force 5N, the static friction will be 5N. If we change the applied force to 10N, then the friction will adjust itself and it will become 10N.