What defines the electrode best?

The correct answer is: Connection between conducting part of circuit and non-metallic part of the circuit.

An electrode is a connection between conducting part of the circuit and the non-metallic part of the circuit.

• In a circuit, the contact for the non-metallic part is made with a semiconductor or electrolyte.
• The contact between the electric conductor of the battery and the non-metallic part is made by the electrode.
• The material used as an electrode depends on the type of the circuit.