Used somewhat loosely, the term "bardo" refers to the state of existence intermediate between two lives on earth. According to Tibetan tradition, after death and before one's next birth, when one's consciousness is not connected with a physical body, one experiences a variety of phenomena. These usually follow a particular sequence of degeneration from, just after death, the clearest experiences of reality of which one is spiritually capable, to, later on, terrifying hallucinations arising from the impulses of one's previous unskilful actions. For the spiritually advanced the bardo offers a state of great opportunity for liberation, since transcendental insight may arise with the direct experience of reality, whilst for others it can become a place of danger as the karmically created hallucinations can impel one into a less than desirable rebirth.
The Bardo Thodol (Bardo Thos-grol), (literally: "liberation through hearing in the intermediate state) the so-called Tibetan Book of the Dead describes bardo experiences. This work actually differentiates the intermediate states between lives into three bardos (themselves further subdivided): # 1 the chikhai bardo or "bardo of the moment of death" # 2 the chonyid bardo or "bardo of the experiencing of reality" # 3 the sidpa bardo or "bardo of rebirth".
The chikhai bardo features the experience of the "clear light of reality", or at least the nearest approximation to it of which one is spiritually capable.
The chonyid bardo features the experience of visions of various Buddha forms (or, again, the nearest approximations of which one is capable).
The sidpa bardo features karmically impelled hallucinations which eventually result in rebirth.
One can compare the descriptions of the Bardo Thodol with accounts of certain "out of the body" experiences described by people who have nearly died in accidents or on the operating table - these typically contain accounts of a "white light", experienced as, somehow, a living being, and of helpful figures corresponding to that person's religious tradition.
The Bardo Thodol also mentions three other bardos: those of "life" (or ordinary waking consciousness), of "dhyana", and of "dream". Thus together the "six bardos" form a classification of states of consciousness into six broad types, and any state of consciousness forms a type of "intermediate state" - intermediate between other states of consciousness. Indeed, one can consider any momentary state of consciousness a bardo, since it lies between our past and future existences; it provides us with the opportunity to experience reality, which is always present but obscured by the projections and confusions due to our previous unskilful actions.
In the West, the term bardo may also refer to times when our usual way of life becomes suspended, as, for example, when we are on retreat. Such times can prove fruitful for spiritual progress, as external constraints diminish, although they offer challenges because our unskilful impulses can come to the fore, just as in the sidpa bardo.
Source for this information is http://bardo.wikiverse.or