Example Concept: In quantum teleportation, a pair of entangled qubits is distributed between the sender (Alice) and the receiver (Bob). Alice performs a joint measurement on her part of the entangled pair and the qubit to be teleported, sending the result to Bob. Bob then applies a corresponding unitary operation to his entangled qubit based on Alice's measurement result. The fidelity of this process is contingent on the purity and strength of the initial entangled state; any decoherence or noise affecting the entangled pair reduces the fidelity of the teleported state.