The anode is defined as the electrode where oxidation occurs.
It means that at the anode's surface, chemical species lose electrons, which flow into the external electrical circuit.
The polarity is context-dependent: in an electrolytic cell (such as those used for galvanizing or hydrogen production), the anode is the positive terminal, driving the non-spontaneous reaction.
Conversely, in a galvanic cell that operates spontaneously (such as a discharging battery), the anode serves as the negative terminal. Its defining characteristic remains the site of electron loss and oxidation, irrespective of its charge label.