The electron, being a charged elementary particle, possesses a nonzero magnetic moment. One of the triumphs of the theory of quantum electrodynamics is its accurate prediction of the electron g -factor, which has been experimentally determined to have the value −2.002 319 304 360 92 (36), with the digits in parentheses denoting measurement uncertainty in the last two digits at one standard deviation. ‍ The value of 2 arises from the Dirac equation, a fundamental equation connecting the electron's spin with its electromagnetic properties, and the deviation from −2 arises from the electron's interaction with the surrounding quantum fields, including its own electromagnetic field and virtual particles.