Definition.
Consciousness is, roughly, the sense of awareness of one’s experiences, both inner and outer. Consciousness, however, has never been conclusively defined or explained. It almost certainly exists not as an absolute state, but rather a spectrum that includes full waking consciousness, reverie states, altered states, dreaming, deep sleep, coma, and others.
A related term, conscious, expresses the state of being present in the ego, as compared to
other figures of the psyche,
which may be understood as unconscious relative to the ego or conscious self. In this sense, consciousness
is the outward-facing part of psyche which interacts with the material world. Again, there is a sense of the relative here.
It may be that what is unconscious is only unconscious relative to the ego, and that the figures we deem ‘unconscious’
have their own form of consciousness. Jung addresses the ‘consciousness’ within the unconscious in
On the Nature of the Psyche.