Unfolding the Enfolded...

Quantum physics tells us that a quantum entity (Nick Herbert calls this, generically, a quon) has a dual mode of existence: When unobserved it exists as a wave of potentials (possibilities); when observed, the wave collapses into a particle (e.g., photon, electron, quark).  Wave function collapse is the event in which the particle appears in one of its many wave potential states/locations.
 

Take your pick: Explanations with static and animated graphics.

Photons, corkscrew waves, interference patterns, standing waves, holograms