The debate over the status of the wavefunction has been at the heart of all the interpretations we have seen thus far. It can be broadly thought of in two ways: either that the wavefunction represents our knowledge of the quantum system, so it is epistemic, and theories that take this stance are called psi-epistemic; or that the wavefunction is part of reality itself, and theories of this persuasion are called psi-ontic (for ontology).
