What is Being? It is what is left when all things fade away. When there is no more experience to be aware of. When your thoughts and feelings and sensations have faded away, or been parked temporarily ‘outside’ of your consciousness.
Some call it ‘That’. Others, just ‘Being’. Or ‘empty space’. Because there is nothing there. No thing. All the things that made you aware of them do not call to you now. They do not exist. At least not in your consciousness, nor your awareness. For you can be aware of something, yet not conscious of it in your mind. So, even the mind at some point goes. And what is left is awareness. Being. For when you Are, you Are Aware. And That is all.