Faraday popularized the general term electrode for a conductor in an electrolyte.
Faraday introduced the word “electrode” in 1833 while developing a systematic vocabulary for electrolysis. An electrode is the conducting part that makes electrical contact with a nonmetallic medium such as an electrolyte. In an electrochemical cell, the two electrodes are conventionally called the anode and cathode.
The terminology came from Faraday’s effort to describe electrochemical experiments precisely. He also helped establish the terms electrolyte and ion, giving scientists a shared language for discussing how electric current passes through solutions and produces chemical change. “Electrode” is formed from Greek roots associated with electricity and a path or way.
A common mix-up is to treat an electrode as synonymous with a catalyst or a molecule. An electrode is not defined by whether it speeds up a reaction or by its molecular identity; it is defined by its electrical role. Electrodes may be made from metals, carbon, or other conductive materials, depending on the cell.
In modern usage, electrodes are found in batteries, electrolysis apparatus, fuel cells, sensors, and medical devices—not only in Faraday’s original laboratory setting.