BOTH cells:- use redox reductions- have the anode as the site of oxidation- have the cathode as the site of reduction- have electrons move from the anode to the cathodeDIFFER in that:- a voltaic cell happens spontaneously while an electrolytic cell requires and outside power source- in a voltaic cell, the anode is positive and the cathode is negative; in an electrolytic cell, the anode is negative and the cathode is positive