Cu2SO4 + Fe → 2 Cu + FeSO4
This is an oxidation-reduction (redox) reaction:
2 CuII + 4 e- → 2 Cu0 (reduction)
SIV - 2 e- → SVI (oxidation)
Fe0 - 2 e- → FeII (oxidation)
Cu2SO4 is an oxidizing agent, Cu2SO4 is a reducing agent, Fe is a reducing agent.