Reality is the sum or aggregate of all that is real or existent within the universe, as opposed to that which is only imaginary, nonexistent or nonactual. The term is also used to refer to the ontological status of things, indicating their existence. In physical terms, reality is the totality of a system, known and unknown.

Reality can be described as the state of things as they are, not as they are imagined to be. Light travels roughly 870,000 times faster than sound and, due to this delay, our brains extrapolate to create a cohesive reality that aligns our perceptions with our physical experiences.

Physical processes, conscious experience, and the social construction of reality are three major philosophical perspectives on the nature of reality.

If I asked you to explain what reality is, you might respond by saying that it is everything ‘out there’. It is the things you can see and touch and hear and how all these factors come together. But what if I told you that the nature of reality is actually something quite different? “Reality is merely an illusion, albeit a very persistent one.”