In contouring nothing is added to the tooth - only taken away. Small imperfections on the outer borders of your tooth are removed by sanding, to create a better looking shape for the tooth.
It is a quick, inexpensive procedure with phenomenal results. Only very small amounts of tooth are removed to prevent post operative sensitivity.
When bigger alterations to the shape and size of the tooth are needed, crowns or veneers will be the treatment of choice.