The privilege granted to the United States Supreme Court to pass judgement on whether the laws passed by Congress are constitutional. It also allows for judging the actions of the president against the Constitution.

It's origin is generally attributed to John Marshall though ideas similar to it had be incorporated in other democratic governments (most notably England when reviewing colonial law.)

It is now considered to be part of the normal system of checks and balances of democratic government though the United States is one of the few that uses it frequently.