In a regular silicon junction diode the positive side is the anode an the negative the cathode.
But when someone uses a Zener diode that operates in reverse bias there is a problem with what constitutes an anode and cathode.
In a Zener diode operating in forward normally the anode is positive and the cathode is negative. But when the diode is operating in reverse bias, what constitutes an anode and a cathode?
Does anode and cathode describe the polarity of the terminal, meaning that now the old anode will be the new cathode, as the polarity has changed, or those terms mean the actual physical terminals of the diode, so now the anode will be negative?