Describes the electrochemical nature of corrosion processes (the anodic and cathodic reaction), the thermodynamics of corrosion processes and reaction kinetics and inhibitors which reduce metallic corrosion by interfering directly with the electrochemical mechanisms of corrosion. Discusses cathodic and anodic inhibition with reference to ph buffering, competitive adsorption, precipitation of insoluble products and protective oxide formation. Also describes inhibition of corrosion in acid solutions and inhibition under non-aqueous conditions. 26 references.