Generally, it states that if a particle can be in each of two states, then it can be in a combination of the two states.
Its implications were challenged in the 1935 Einstein, Podolsky, and Rosen article titled ―Can Quantum-Mechanical  Description of Physical Reality be Considered Complete?‖ In a quantum computer, it allows for qubits to hold not only  ones or zeroes, but many combinations of the two. Generally, it states that if a particle can be in each of two states, then it can be in a combination of the two states. FTP, name this quantum principle, famously illustrated by Schrodinger‘s  simultaneously living and dead cat, and whose consequences include quantum entanglement and spooky action-at-a-  distance.
Its implications were challenged in the 1935 Einstein, Podolsky, and Rosen article titled ―Can Quantum-Mechanical  Description of Physical Reality be Considered Complete?‖
Quantum Superposition