Example Concept: Quantum error correction uses codes like the Shor code or the surface code to encode logical qubits into a larger number of physical qubits. These codes are designed to detect and correct certain types of errors, such as bit-flip or phase-flip errors, by using redundancy and entanglement. By measuring auxiliary qubits (ancillas) without disturbing the encoded information, QEC identifies errors and applies corrective operations, thus preserving the integrity of quantum computations.