No interference with the game
The IFAB required that goal-line technology was not to interfere with the game. As a consequence the requirements were set up determining that only the match officials are to receive a signal to indicated whether or not the ball has crossed the line. The information is transmitted within one second which ensures immediate response from the referee. Due to this design there are no stoppages or other forms of interference in the game.
Support for the match officials
The match officials are the only ones to receive the signal on their watches. Unless there is a conscious choice by the competition organiser to show a reply, the information is only available to the referee and helps in challenging situations.