Polarity

Polarity is the poles of the electric currents. There are either positive poles or negative pole.

The electrode on many electrotherapy devices have one negative electrode and one positive electrode

ANODE (+)

Anode is the positive electrode; is usually red and is marked with a P or a Plus sign (➕)

CATHODE (-)

Cathode is the negative electrode; is usually black and is marked with an N or a Minus sign (➖)