This is usually thin pieces of porcelain that are lab made and added to the teeth to improve the appearance and colour of the teeth.
What are Veneers?

What are the down points?
It can be costly depending how many veneers a person may wish, but a person much be careful and take care of them
What are the good points?
Usually the results can last a long time and the colour rarely changes when taken care of properly, ask your dentist for more information.