An extra number of points (moku) given to White, which may be used in various ways:

1. To compensate for the alleged advantage Black has when playing the first stone.
   
2. To avoid a draw (jigo) as a game result by using a fractional number (for example 6.5 komi).
   
3. To act as a form of compensation between players of different strength.
   For further explanations see: What is the difference between conventional and proper handicap?