Reality is the totality of existence or what all existing entities have in common. It is often contrasted with appearance, opposing what is with what seems to be, although the accuracy and fundamentality of this contrast are disputed. Various criteria for distinguishing real from unreal entities have been proposed, including causal powers, mind-independence, and being non-illusory. The concept of reality overlaps with notions such as being, existence, world, actuality, and truth.

Not to be confused with Realty.

For other uses, see Reality (disambiguation).

Philosophers debate what kinds of things are part of reality and how they are organized. Proposed constituents include particulars and universals, concrete and abstract objects, facts, events, and elementary particles. Discussions of the structure of reality address the relation between parts and wholes, the distinction between fundamental and non-fundamental entities, the idea that reality forms a hierarchy of levels, and the roles of unity and multiplicity in – debates. Other topics are and as frameworks that organize among entities, and describing regularities or general patterns of how entities interact and changes unfold.