What is a qubit?

A qubit, or quantum bit, is the fundamental unit of quantum information. It represents the quantum version of the classical binary bit. While a classical bit can be in one of two states, 0 or 1, a qubit can be in a state called superposition, where it can be 0, 1, or any quantum superposition of these states. This means a qubit can represent both 0 and 1 at the same time, a property that allows quantum computers to process information in a fundamentally different way than classical computers. Additionally, qubits can be entangled, a quantum phenomenon where the state of one qubit is directly related to the state of another, no matter the distance between them. This entanglement and superposition are what give quantum computers their potential power, enabling them to solve certain types of problems much more efficiently than classical computers.