qubit
The basic unit of information in a quantum computer, the quantum version of a bit.
An ordinary bit is always either 0 or 1. A qubit can hold a blend of 0 and 1 until it is measured, and then it gives a single answer. Qubits are made in several ways, such as tiny superconducting circuits or trapped atoms. Machines are often described by how many qubits they have. More qubits allow bigger problems, but are harder to keep error-free.
Think of it as
A bit is a light switch, on or off. A qubit is more like a dimmer that is only read as on or off at the moment you look.
Example
One company's machine has 100 qubits and another's has 50. The first can, in principle, take on bigger problems. Whether it gives better answers depends on how often its qubits make errors.
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