(QUantum BIT) A unit of data in a quantum computer. The "bit" in qubit is somewhat misleading. Unlike a bit (binary digit) in a digital computer, which can hold a 0 or 1, a qubit can represent both a 0 and 1 at the same time. In addition, the qubit is not a storage cell as in RAM or flash memory but is typically one or more electrons. See quantum computing.