Anodizing: A protective metal coating. It is usually chemically induced and non-organic. Used to enhance scratch and wear resistance, typically on aluminum materials.

Bluing: Same as anodizing, but typically used on steel based metals.

Coating: An organic based protective coating.

Hard coat anodizing: A heavy anodizing applied for extreme heat and scratch résistance.

Penetration depth or etching depth: Depth below the surface which can be controlled by customer specification.