It is one of the best-tested theories of physics, and we use it all the time. On the face of it, however, the quantum realm is extraordinary: Within it, quantum objects can be “in two places at once”; they can move through barriers; and share a connection no matter how far apart they are.

MW is more a psychological way to imagine things rather than a framework to calculate or predict things quantitatively. Consistent Histories can do the calculation, and it was the framework where decoherence was properly formulated - quantitatively.

In quantum mechanics, the consistent histories or simply "consistent quantum theory" interpretation generalizes the complementarity aspect of the conventional Copenhagen interpretation. The approach is sometimes called decoherent histories and in other work decoherent histories are more specialized.

The Many-Worlds Interpretation (MWI) of quantum mechanics holds that there are many worlds which exist in parallel at the same space and time as our own. The existence of the other worlds makes it possible to remove randomness and action at a distance from quantum theory and thus from all physics.