What is the difference between a porcelain veneer and a crown?

Ceramic veneers and crowns may be made of the same materials.  The difference between the two is how much of the tooth is covered by the restoration.  A crown covers most or all of the tooth that is exposed out of the gums, almost like putting a tooth-shaped bucket over the nub of remaining natural tooth.  A ceramic veneer covers and restores only the side of the tooth that faces out and shows when you smile, somewhat like putting a tooth-shaped artificial fingernail on the front of the tooth.