Quantum computers are fundamentally different from classical computers in the way they process information. While classical computers use bits, which can be either 0 or 1, quantum computers use quantum bits or qubits, which can exist in multiple states simultaneously. This property of qubits, known as superposition, allows quantum computers to perform certain types of calculations much faster than classical computers. Additionally, quantum computers can use entanglement, a phenomenon where two particles can become linked in a way that their states are correlated, to perform certain types of calculations that are impossible for classical computers.