Redox; reduction and oxidation - one cannot occur without the other - is best defined as the transfer of electrons from one chemical element to another.
Electrochemical cells I
Topic 9.2 Two types of electrochemical cells; each the opposite of the other!
Electrochemical cells II
Topic 19.1 Further exploration of our understanding of electrochemical cells.
Oxidation and reduction
Topic 9.1 Understanding oxidation and reduction in terms of 'which element owns the electrons?'.