This phenomenon is the hardest to understand and visualize since nothing in our mundane, day to day lives behave this way. When in superposition (a special state a particle can be in) a property of a quantum particle can be in multiple states at the same time. (Ex – spin of an electron can be up and down at the same time).
An object can be in superposition only when nothing is interacting with it. The difficulty is that if we want to measure a property of that object, we have to interact with the object in some manner. Therefore, as soon as the superposition is observed, it will collapse and revert to one of the more classical values (0 or 1) randomly. Now, if this experiment is performed multiple times, a probability distribution for each classical state can be observed.
