Consciousness can metaphorically be thought of as the fundamental energy that is the media of reality. It is one of the two assumptions put forth in MBT, and it is a "mystical" (beyond objective knowing from the PMR point of view) assumption in that it requires our spatially limited worldview and cultural beliefs to stretch beyond their normal patterns.[MBT Trilogy 1]
It is the interplay of consciousness (the "stuff") and evolution (the "process") that creates reality as we know it.
Consciousness as it Exists for The One Consciousness
Ultimately, we cannot know the nature of Consciousness as experienced by The One Consciousness or AUM. It is both beyond our access and beyond our comprehension if it were accessible. See The MBT Model Link Page for what we do know about the nature of the Consciousness of The One and how it arose.
Consciousness as it is Experienced by us as IUOCs
To say that we are an Individuated Unit Of Consciousness is in a sense a misnomer. We do not generate our own consciousness but rather are the recipients of a data stream generated to represent our experience within a Virtual Reality as created by The One Consciousness through the agency of The Big Computer and its sub function as the VRRE. We then interact with this data stream and thus with the Rule Set of the VR and with those other IUOCs participating within and represented within that particular VR. We subjectively interpret and perceive this data stream representing our experience as if we existed 'within' that VR as opposed to actually existing within the VR as an actual Reality. Thus our whole existence within a VR is a simulation. This includes our perception of what we experience as our own "thoughts" which must be selected by the VRRE from the total volume of our thoughts as an IUOC because of the vast differential between the base speed rate (smallest possible Delta t) at which our IUOC operates versus our ability to perceive within the various VRs.