Consciousness has traditionally been portrayed as some mystical aspect of the mind. Something hard to define what it is, or even what forms of life have it. But perhaps it is not so complex and mystical a thing.
I was working on the Pandora project recently and modeling Pandora's mind and senses. Originally I had a Sense have input and output, both tied to the active memory, but the output did not seem correct, how could the Sense decide what to do? So then I realized I was missing something, the output should take an article of memory, and something must control what to send as output. Basically I needed a consciousness.
So it was quite easy to add another Thought subclass to model a Consciousness, basically a Thought whose only purpose is to monitor the Sense's inputs and decide on the output.
So what is a consciousness? It is basically a thought process that controls the senses. So what has a consciousness? Well since it is just something that controls senses, there would be little point in anything without senses having one.