A term originating from an alternative belief structure
Within the considerations of this belief system, the Void is believed to be a non-physical plane of existence where all souls are thought to arrive immediately after death; a place where souls congregate and contemplate before making the next excursion into one of the physical realms.
The Void is a term originating from a belief structure which may be broadly called the ‘Vibrational' or ‘Harmonic' model of existence, wherein the vibrational frequency of energy (thought by practitioners to make up the basis of all matter), determines at what level of awareness and existence matter is maintained. The Void is sometimes also referred to as the ‘5th density', according to the similar and more recently occurring, ‘Density' model of existence. (See Density belief system.)
It is believed that the original source of these models stem in part from certain Chinese martial arts practitioners and related Eastern philosophies. Long-standing and historically recognized names for these belief systems do not appear to be available. Their basic belief structures, however, have recently been embraced by and labeled among, ‘New Age Philosophies.' –A dubious term commonly associated with non-critical belief in junk science and occult spirituality.
Completely Unverifiable Personal Opinion: The study of non-standard belief models has always struck me as a thoroughly fascinating anthropological exercise. Of interesting note is the fact that in each of these systems, an over-arching deity is entirely absent, the structures all appearing to be based upon a net-work system, wherein all souls are interconnected in such a way that they together form a large, singular entity sometimes broadly referred to as God, (although in a different sense than that word is understood by the older, classical models).
It is possible that this trend has been inspired by the newly rising awareness of modern communications and knowledge dissemination systems, (i.e. cell phones, the internet, etc.) which utilize non-hierarchal cell structures as their basis. –Although it has also been argued that the reverse is true.
See Density belief system and Harmonic belief system for further notes on each.