What is the difference between reconstructive and cosmetic plastic surgery?

The goal of reconstructive surgery is to correct defects (as in breast reconstruction after cancer surgery) and to restore form or function to a part of the face or body which is considered to be outside the range of normal.  Cosmetic surgery procedures are designed to enhance a part of the face or body which is actually within the range of normal, but there is a personal desire to improve upon it in some way.