Just as you furnish your home to make it look nicer, you can furnish your teeth with veneers to improve their appearance.
One veneer definition from a medical dictionary is:
A plastic or porcelain coating bonded to the surface of a cosmetically imperfect tooth.
The most natural-looking and durable veneers are made from porcelain, but composite materials are more economical. They can be applied in cases where the aim is to improve the appearance of teeth rather than to repair damage from decay or trauma.