NIHILISM is the belief that life, existence itself, has no ultimate, cosmic or eternal meaning or significance. From this perspective, it is, thus, a void.
Consequently, it would follow that reality has no truth or morality of its own, that it cannot, and does not, speak for itself and that, as a further consequence, that it cannot, and does not, care.
As a result, there are those who despise both nihilism and nihilists because they believe that if nihilism is true then there is nothing to stop someone becoming a Nazi, a terrorist or in general leading both terrible and destructive lives.
Nihilism, then, is ultimately the view that life must be lived without ultimate grounds or foundations, that such things, where they exist, are pure invention.
This, I believe, makes it politically interesting.