The basic difference between the concept of Fundamental Rights and that of the Natural Rights is regarding their origin. Fundamental Rights are created by the state and guaranteed by its constitution. They exist in the state of society. But Natural Rights are believed to have existed before the state came into being.
They are prior to it. Fundamental Rights lie at the very foundation of human existence, while the Natural Rights lie in the nature of man or of the universe. Secondly, Fundamental Rights are sanctioned by the state through its judicial organ, while the Natural Rights are enforced by the nature, which rely means they are not enforced at all.
Thirdly, although both the theories of fundamental and Natural Rights consider these rights as inalienable and inherent in man, but the theory of Natural Rights upholds them even against the state, which cannot limit or deny them.