In Buddhism, Sunyata शून्यता ("Emptiness, illusory nature of phenomena, voidness, non-reality").
The ultimate nature of reality, which is impossible to convey in words. In Buddhist philosophy, it is described as paramarthasatya (ultimate truth), dharmata (actual reality), and tathata (suchness), each of which attempt to communicate the total absence of self-identity ("I") and inherent existence. Only through the experience of the voidness or emptiness can one understand it, and that experience can only be reached through a very specific type of meditation.
"Transcendent wisdom is inexpressible and inconceivable. Unborn and unceasing, it has the nature of space; It is realized through an individual's discernment And is the object of pristine awareness. It is the mother of all Buddhas throughout the three periods of time." —Buddha Shakyamuni
"Buddhist Enlightenment is not gained through holding onto or inflating one's self-awareness. On the contrary, it is gained through killing or crushing any attachment to this illuminating consciousness; only by transcending it may one come to the innermost core of Mind—the perfectly free and thoroughly nonsubstantial illuminating-Voidness. This illuminating-Void character, empty yet dynamic, is the Essence (Chinese: ti) of the mind. The important point here is that when the word "Essence" is mentioned, people immediately think of something quintessentialy concrete; and when the word "Void" is mentioned, they automatically envision a dead and static "nothingness." Both of these conceptions miss the meanings of the Chinese word ti (Essence) and the Sanskrit word Sunyata (Voidness), and expose the limitation of the finite and one-sided way of human thinking. The ordinary way of thinking is to accept the idea that something is existent or nonexistent, but never that it is both existent and nonexistent at the same time. A is A or not A; but never is it both A and not A simultaneously. In the same way, the verdict of common sense on Voidness versus existence is: "Voidness is not existence, nor is existence Voidness." This pattern of reasoning, regarded as the correct and rational way of thinking, is advocated by logicians as a sine qua non and is accepted by common sense for all practical purposes. But Buddhism does not invariably follow this sine qua non, especially when it deals with the truth of Sunyata. It says: "Form does not differ from Voidness, and Voidness does not differ from Form; Form is Voidness and Voidness is Form." Buddhism also says that it is owing to Voidness that things can exist and, because of the very fact that things do exist, they must be Void. It emphasizes that Voidness and existence are complementary to each other and not in opposition to each other; they include and embrace, rather than exclude or negate each other. When ordinary sentient beings see an object, they see only its existent, not its void, aspect. But an enlightened being sees both aspects at the same time. This nondistinguishment, or "unification" as some people like to call it, of Voidness and existence, is the so-called Nonabiding Middle Way Doctrine of Mahayana Buddhism. Therefore, Voidness, as understood in Buddhism, is not something negative, nor does it mean absence or extinction. Voidness is simply a term denoting the nonsubstantial and nonself nature of beings, and a pointer indicating the state of absolute nonattachment and freedom. Voidness is not easily explained. It is not definable or describable. As Zen Master Huai Jang has said, "Anything that I say will miss the point." —Garma C.C. Chang, The Practice of Zen (1959)
"Those who are ignorant of the void cannot achieve liberation. These confused minds wander in the prison of the six realms." —Bodhichittavivarana