A sacrificial anode is a device used to protect a metal structure from corrosion. It is made of a more reactive metal, often zinc or magnesium, which is more likely to oxidize than the underlying metal it is protecting. This process, called cathodic protection, prevents the underlying metal from corroding. Other synonyms for sacrificial anode include cathodic sacrificial anode, sacrificial electrode, corrosion inhibitor, cathode protection, and electrolytic corrosion. These terms are interchangeable and refer to the same protective mechanism. The use of sacrificial anodes is vital in many industries, including ships, pipelines, and offshore oil platforms, where exposure to saltwater can lead to severe corrosion.