In contrast with the Daniell batterie, in this experiment the copper is only used as electrodes. This cell works because the two solutions of copper sulfate have different concentrations.

Due to the fact that the two solutions have different concentrations, the copper electrode dived in the less concentrated solution works as anode (electrons source). It frees Cu²⁺ ions to increase the concentration of the solution and, consequently, it frees two electrons to the cathode per each freed ion. On the other hand, in the electrode dived in the most concentrated solution (cathode), the electrons arrived from the anode react in the surface of the electrode with the solution ions Cu²⁺, forming an metallic copper deposit in its surface. Don't forget, enjoy learning how science works!