Copenhagen Interpretation is the principle known as complementarity, which that the wave and particle nature of objects can be regarded as complementary aspects of a single reality, like the two sides of a coin. It remains one of the most commonly taught interpretations of quantum mechanics. The adoption of the Copenhagen Interpretation for quantum phenomenon poses a sharp divide between classical or macroscopic physics and quantum or microscopic physics. This feature is known as wavefunction collapse. It include the many-worlds interpretation, the De Broglie-Bohm (pilot-wave) interpretation, and quantum decoherence theories.