Bon is the title given to the royal priests who performed rituals for the Tibetan Yarlung kings.
Bon, or Bon-Po, is also the name of the religion itself, which is Tibet’s oldest spiritual tradition. The Bon-Po religion is a heterodox religion developed around the ``four ways of gods and men'': divination, exorcism, coercion, and guiding the human spirits. Another major feature of Bon is shamanism, or the belief in a world of gods which could only be divined by the shamans.
Bon is significant in the development of Buddhism in Tibet, as it was one of many influences on the religion as it developed in that area. Through time and interactions with Buddhism, it also became an entire school of Tibetan Buddhism, before being discouraged and rejected in later years.
``Practitioners of the spiritual path are divided into those of a superior capacity, those of an intermediate capacity, and those of an inferior capacity. In addition to these three, the individual possessing an exceedingly superior spiritual capacity may obtain liberation without the need to undergo death and the Bardo experience because such an individual has attained liberation from Samsara in one's present lifetime. This process is known as Phowa Chenpo or the Great Transfer, where one transforms directly into a Body of Light without the prior necessity of going through the death process.'' – Commentary to the Bonpo Book of the Dead by Vajranatha.