An anode is an electrode through which the conventional current enters into a polarized electrical device. This contrasts with a cathode, an electrode through which conventional current leaves an electrical device. A common mnemonic is ACID, for "anode current into device". The direction of conventional current (the flow of positive charges) in a circuit is opposite to the direction of electron flow, so (negatively charged) electrons flow out the anode of a galvanic cell, into an outside or external circuit connected to the cell. In both a galvanic cell and an electrolytic cell, the anode is the electrode at which the oxidation reaction occurs.
In an electrolytic cell, the anode is the wire or plate having excess positive charge. Consequently, anions will tend to move towards the anode where they can undergo oxidation.
Historically, the anode has also been known as the zincode.