Galvanic versus electrolytic cell Tamil revision mind map as a side by side comparison: the galvanic cell converting spontaneous chemical energy to electricity with a negative anode and positive cathode, versus the electrolytic cell requiring external electricity to drive a non-spontaneous reaction with a positive anode and negative cathode, sharing the unchanged rule that oxidation always occurs at the anode and reduction always at the cathode, plus a Faraday's laws calculation strip covering charge equals current times time, moles of electrons equals charge divided by the Faraday constant, and a worked example depositing copper.