Quantum computing
Superposition
The property that lets a quantum system hold a combination of states at once. Superposition alone does not make quantum computers fast — the speedups come from interference that amplifies correct answers.
Related terms
Qubit
The basic unit of quantum information, able to hold a superposition of 0 and 1 rather than one definite value. Physical qubits are noisy; useful computation needs many of them combined into error-corrected logical qubits.
Quantum entanglement
A correlation between quantum systems such that the state of one cannot be described independently of the other, regardless of distance. It is a resource for quantum algorithms and for quantum key distribution.