I had to write an essay about electrochemical cells for chemistry, this is part of it:

To better explain this idea of an electrochemical cell, I have chosen an electron named Jeffery whom we will follow throughout this circuit. Jeffery originates as part of the solid Zinc strip that is in solution. He is soon ripped apart from his Zn2+ buddy, to which he is usually attached at the hip. Jeffery flies up the electrode that is attached to the strip of zinc at the anode. He flies through the wires all the way onto the solid copper strip to which he quickly finds a new BFF, Cu2+! Here he and a Cu2+ ion combine and make a Cu(s) molecule, thus increasing the mass of the Copper strip at the cathode. The reduction is taking place at the cathode, so therefore the Zn2+ ion that Jeff left is the reducing agent, and the Cu2+ ion that Jeff made friends with is the oxidizing agent.