In dentistry, a veneer is a thin layer of restorative material placed over a tooth surface, either to improve the aesthetics of a tooth, or to protect a damaged tooth surface. 

There are two main types of material used to fabricate a veneer, composite and dental porcelain. 

A composite veneer may be directly placed (built-up in the mouth), or indirectly fabricated by a dental technician in a dental laboratory, and later bonded to the tooth, typically using a resin cement such as Panavia. 
In contrast, a porcelain veneer may only be indirectly fabricated.