Fault-tolerant quantum computing is a method that ensures quantum computers can operate correctly even when errors occur. Quantum bits, or qubits, are sensitive to disturbances, which can lead to mistakes in calculations. Fault tolerance involves using techniques like quantum error correction to detect and fix these errors, allowing computations to continue reliably. This approach is crucial for the practical use of quantum computers in solving complex problems. By maintaining the integrity of calculations, fault-tolerant quantum computing aims to harness the full potential of quantum mechanics, paving the way for advancements in fields such as cryptography, materials science, and artificial intelligence.