In quantum information science, monogamy is a fundamental property of quantum entanglement that describes the fact that entanglement cannot be freely shared between arbitrarily many parties. According to monogamy, in order for two qubits A and B to be maximally entangled, they must not be entangled with any third qubit C whatsoever. Even if A and B are not maximally entangled, the degree of entanglement between them constrains the degree to which A can be entangled with C. In full generality, for qubits , monogamy is characterized by the Coffman-Kundu-Wootters (CKW) inequality, which states that