Zinc plating

Zinc plating (also known as electro-galvanizing) is an electrochemical process that deposits a thin layer of zinc onto metal surfaces—typically steel or iron—to provide excellent corrosion protection.
The zinc acts as a sacrificial coating: it corrodes preferentially (sacrificing itself) before the underlying metal, offering both a physical barrier against moisture and oxygen and cathodic (galvanic) protection even if it gets scratched.