What is defined as a luminous discharge of electricity between two electrodes?

A luminous discharge of electricity between two electrodes is termed an electric arc. This phenomenon occurs when a high voltage creates a conductive path through the air or another medium between two conductive materials, resulting in a visible and bright arc of electricity. The temperature of an electric arc can be extremely high, often exceeding several thousand degrees Celsius, which allows it to generate light, hence the term "luminous."

This description captures the essence of how electric arcs function compared to other concepts such as an electric field, which refers to the influence exerted by an electric charge on other charges in the vicinity, but does not necessarily involve a physical discharge or illumination. An electrical circuit pertains to a closed loop that allows current to flow but does not focus on the discharge between two points. Lastly, a power surge signifies a sudden increase in electrical energy in a circuit and does not directly involve the concept of discharge between two electrodes. Thus, recognizing the distinct nature of an electric arc clarifies its definition as a luminous discharge that occurs specifically in the context described.