What exactly is nihilism?

Nihilism (from the Latin nihil, nothing) is a philosophical position that argues that existence is without objective meaning, purpose, or intrinsic value. Nihilists generally ert that objective morality does not exist, so subsequently there is no objective moral value with which to logically prefer one action over another. Nihilists who argue that there is no objective morality may claim that existence has no intrinsic higher meaning or goal. They may also claim that there is no reasonable proof or argument for the existence of a higher ruler or creator, or posit that even if higher rulers or creators exist, humanity has no moral obligation to worship them.