According to Vedanta, what is “real” is what cannot be negated, that which is always true in all places and at all times, or more accurately that which is the substratum of the entire time-space continuum that defines the apparent reality. Reality is essentially that upon which all apparent objects depend for their existence, but which itself is self-dependent and self-luminous and, therefore, ever-free of all the phenomena appearing within and made of it. In other words, though all objects are me in the sense that they are reflected awareness, I – pure awareness – remain untouched by and eternally independent of all objects.
Contrary to some interpretations of Buddhism and the proclamations of many Neo-Advaitans, Vedanta does not say that the realm of dependent objects does not exist. Our direct experience attests to the existence of objects. If objects did not existent, we would not experience them. The issue regarding objects is not whether or not they exist, but whether or not they are real.
According to Vedanta, there are three ontological categories: the real (i.e. satya), the not-real (i.e. asat), and the apparent (i.e. mithya).
Sat means “being” or “what is,” so satya refers to what was previously described as that which cannot be negated, or that which does not change. It cannot be enhanced or diminished. It is what is always good. There is only one “thing” that is ultimately real: the self, pure awareness, me.
Asat refers to that which does not and cannot exist. The horns of a hare, the fur of a fish.