The terms "anti-corrosion" or "corrosion-inhibiting" are used to describe measures taken to suppress or slow down the destruction of materials, usually metal, through the action of water and oxygen. Such measures are based on one of two fundamentally different methods:
1. Passive corrosion protection: The metal surface is protected from contact with water and oxygen, e.g. by means of a coated finish.
2. Active (cathodic) corrosion protection:The metal requiring protection is either coated by a less noble metal (i.e. a metal lower in the galvanic series) or connected to a "sacrificial anode". Although this does not prevent corrosion, it is only the "sacrificial metal" and not the protected metal that decomposes.
With silicate-bound zinc coatings, the two mechanisms operate in tandem, thus offering double protection.