Quantum Volume – A figure-of-merit with which to compare different devices. It captures the challenge of implementing a random set of generic 2Q gate operations between randomly selected qubits. It naturally builds in the degree to which device control and low-level compilation is able to compensate for gate errors and compose gates in terms of the device’s native gate-set and connectivity. By design it gives equal weight to the number of qubits that can be managed and the depth of circuit iterations that can be performed. Crudely speaking it captures the largest ‘square-shaped’ circuit that the device can on average successfully run. Originally introduced and championed by IBM.