REDUCTION
Reduction is a process, opposite to oxidation, which is deoxidation (taking oxygen away). The terms "oxidation" and "reduction" can be generalized, if it is taken into account that oxygen almost always withdraws electrons out of the element bonded to it. Thereby, the essence of oxidation is in loss of electrons by the oxidized substance. All the way round, during reduction that substance receives back the electrons, which it gave away before. The essence of reduction is in joining electrons by the substance being reduced.