When the skin is damaged, it will nearly always heal with a scar. Different people scar in better ways than others, but in general those with very dark skin or very fair skin often produce very poor scars.
If a scar is particularly poor, or in a prominent position, it is possible to revise it in order to make it less obvious and more aesthetically pleasing. It is most commonly used on scars caused by accidents, as these tend to be less neat by their very nature.
There are a number of methods for carrying out the procedure. Steroid injections help to flatten scars and often produce excellent results. Laser skin resurfacing is used on pitted scars such as those caused by Acne.
The other option is surgical. The old scar is cut away and plastic surgery is used to repair the area. While you will still be left with a scar, it will be much neater than the original. The size and location of the scar will determine the exact procedure used and how long you will need to spend in hospital.