Turiya
तुरीय (turiya)
The fourth state - pure awareness underlying waking, dreaming, and dreamless sleep.
Vedantic thought describes three ordinary states of consciousness: waking, dreaming, and dreamless sleep. Turiya, literally the fourth, names a state underlying all three, understood not as another state alongside them but as the awareness in which all three arise and pass.
This is a subtle distinction and easy to flatten into something it is not. Turiya is not a fourth experience to be had, in the way waking or dreaming are experiences. It is described as the witnessing awareness present in every state, usually unnoticed precisely because it never itself changes.
The practical use of the concept, for those without an interest in its full metaphysics, is a simple reframe: whatever state you are currently in, waking, dreaming, or something between, there is a constancy underneath the shifting content, worth noticing on its own terms.