Answer:
It is called a reduction-oxidation, oxide-reduction reaction, or simply as a redox reaction, any chemical reaction in which one or more electrons are transferred between the reactants
Redox battery is an example of both a Flow Battery and a two electrolyte system.In this case, it depends on two different active aqueous electrolytes of vanadium dissolved in sulfuric acid separated by a membrane at which ionic interchange takes place.
Thats my opinión though.