Emptiness, otherwise translated as "voidness," is asserted by Mahayana Buddhism as the manner of existence of all phenomena. Rather than being formulated as an affirmation phenomenon (how things do exist), it is formulated merely in terms of a negation phenomenon (how things do not exist). It is the absence of ways of existing that do not exist at all. This does not imply the nihilist extreme that nothing exists. Emptiness does not mean nonexistence in general, just the nonexistence of what in fact does not exist and never can exist. Nothing exists in the manner in which our limited minds make it appear to exist. Each of the Mahayana tenet systems negates a different way of existing that all phenomena lack.
Tibetan: སྟོང་པ་ཉིད། stong-pa-nyid