The afterlife, or life after death, is a generic term referring to a "continuation" of existence, typically spiritual, experiential, or ghost-like, beyond this world (eg. planes of existence), or after physical death (eg. near-death experience, reincarnation). The major views in this area derive from religion, esotericism, metaphysics, and science. Also there are those with opposite views, such as the materialist-reductionists, who state that the topic is supernatural, therefore does not really exist or is unknowable.