Electrochemistry is the study of chemical processes that cause electrons to move. This movement of electrons is called electricity, which can be generated by movements of electrons from one element to another in a reaction known as an oxidation-reduction ("redox") reaction. In this chapter, the married subjects of thermodynamics and equilibrium will be expanded to a troika by including electrochemistry. The ability to "steal" and "donate" electrons will be introduced and discussed in the context of free energies, enthalpies, entropies and equilibrium constants.