A quantum circuit is a model for quantum computation in which a computation is broken down into a sequence of quantum gates, which manipulate quantum bits (qubits). Just as classical circuits operate using classical bits (0s and 1s), quantum circuits utilize the principles of quantum mechanics to perform operations on qubits, which can exist in superpositions of states. ### Key Components of a Quantum Circuit: 1. **Qubits**: The basic unit of quantum information, analogous to classical bits.