One of the fundamental phenomena in quantum physics and computer programming is quantum entanglement. This phenomenon occurs in the case of two quantum particels which are entangled and that causes that making a measurement on one of these qubits will not only determine the value for this qubit, but will also determine the value for the other qubit, immediately. Regardless of the distance between them. The CNOT gate described in the previous article is most often used to entangle qubits. However, nothing stands in the way of entangling more qubits in more advanced algorithms.