https://www.researchgate.net/post/What_is_the_physical_significance_of_Parity_What_does_it_actually_Mean

few answers

Parity is a physical property of a wave function which specifies the wave function's behavior under simultaneous reflection of all spatial coordinates of the wave function through the origin.

Parity is defined as the eigenvalue of the operation of space inversion. Parity is a concept that meaning only for waves and therefore has no meaning in classical particle physics.

The conservation of parity is a consequence of the invasion symmetry of space.

All the strong interactions between elementary particles (for example, nuclear forces) and the electromagnetic interactions are symmetrical to the inversion, so that parity is conserved by these interactions.

Atomic and nuclear energy states are characterized by a definite parity, and the conservation of parity has important bearing on atomic and nuclear reactions. Operations representing dynamical variables may also be classified in terms of the parity concept, depending upon how they are affected by an inversion of their spatial coordinates.