Finishes are used in the final part of the construction or manufacturing process, forming the final surface of an element. They can protect the element they finish from impact, water, frost, corrosion, abrasion, and so on, and/or they can be decorative.
Finishes commonly relate to internal surfaces, but they may also be applied to external elements. They can be applied wet or dry. Some elements are self-finished, that is the final surface is part of the material the element is formed from.
The application of finishes may involve the build up of more than layer, which whilst some of the layers will form the final exposed surface, they are nonetheless considered to be finishes. For example, an undercoat or primer might be applied to a wall before the final paint.