Fidelity

Qubit fidelity describes how close a given quantum state is close to a target state. Gate fidelity (often termed 1Q fidelity for 1-qubit gates and 2Q fidelity for 2-qubit gates) describes how accurate a quantum operation (or gate) is. It is a measure of how close an operation gets to its intended behavior in execution. This is often used alongside gate speed, which is the time it takes for a gate to complete its operation.