Oxidation-reduction, often called redox, refers to a chemical process where electrons are transferred between substances. In this process, one substance loses electrons and undergoes oxidation, while another gains electrons and undergoes reduction. This transfer of electrons is essential in various chemical reactions, including those that occur in batteries and biological systems. Redox reactions are crucial for energy production in living organisms. For example, during cellular respiration, glucose is oxidized to produce energy, while oxygen is reduced to form water. Understanding redox processes helps in fields like chemistry, biology, and environmental science, as they play a key role in many natural and industrial processes.