Qubits, or quantum bits, are the fundamental units of quantum information. Unlike classical bits, which can be either 0 or 1, qubits can exist in a superposition of both states simultaneously. This property, along with quantum entanglement (where qubits become interconnected and the state of one instantly affects the state of another, regardless of distance). The principles of quantum mechanics govern the behavior of qubits, and harnessing their unique properties gives quantum computers their potential power.