The difference is one of justification: we accord "natural" rights to human beings on the basis of the belief that every person is valuable and deserves certain

The difference is one of justification: we accord "natural" rights to human beings on the basis of the belief that every person is valuable and deserves certain protections and opportunities (e.g. a right to life, a right to education). Non-natural rights are instead determined on the basis of the belief that they provide an on-net benefit to the general welfare, even if not every person needs them or benefits from them.