Base reality is defined as the objective and fundamental reality that exists independently of any subjective experience or perception. It is the highest and ultimate level of reality in everythingness. When we refer to everything that exists, we usually use the word “universe”, “cosmos”, or “world”, but, the leading theory in quantum cosmology (Many-worlds Interpretation) states that there are many universes in a multiverse that we live in, and our universe is just yet another universe part of a multiverse containing infinite (or at least many) other universes. So, when you say “the universe” you’re just referring to the one we live in. There are more.
Assuming extraterrestrial life exists (which is pretty much a certainty given the vastness of our universe), it is fair to say that we live in a pretty ordinary solar system, in a pretty ordinary galaxy, in a pretty ordinary galactic cluster. Why should our universe be special? At one point in history, humans believed that Earth was the only planet in existence, until we discovered the existence of many other planets. Similarly, we were once unaware of the existence of multiple solar systems, until we discovered them. Later on, we thought that the Milky Way was the only galaxy in the universe, but we have since discovered the existence of countless others. Given these discoveries, it seems logical that there is a high probability that we live in one of many universes. Then comes the question of what is beyond those universes.
Is any of this even real? It depends on what you define reality is. If your definition matches ours, which was mentioned at the beginning of this post, then we, more than likely, do not live anywhere even near base reality. It’s of course a possibility that we live in some sort of container equivalent to a computer simulation on Earth, and none of this supercluster stuff is even “real.” For now, our focus remains on maximizing the potential of our current existence, wherever it may be situated within the layers of reality.