Cathodic Protection Systems are techniques used to prevent corrosion on metal surfaces, particularly those exposed to moisture or soil. This is achieved by making the metal structure the cathode of an electrochemical cell, which reduces the oxidation process that leads to corrosion. Common applications include pipelines, storage tanks, and ships. There are two main types of cathodic protection: sacrificial anode systems and impressed current systems. In sacrificial anode systems, a more reactive metal is attached to the structure, which corrodes instead of the protected metal. Impressed current systems use an external power source to provide a continuous flow of electrical current, further enhancing protection against corrosion.