Adjudication is an independent decision (usually by a strong, impartial chess player) as to whether an unfinished game should be scored as draw or a win for one of the players on best play by both players.  It may be used by a tournament director for pairing purposes.  It may be used to give a result of a game when there is not enough time to complete the game.  Some correspondence games have a time limit for the event.  Each player may submit the game for adjudication when that time limit is up.