In association football, goal-line technology (sometimes referred to as a Goal Decision System)[1] is the use of electronic aid to determine if a goal has been scored or not. In detail, it is a method used to determine when the ball has completely crossed the goal line in between the goal-posts and underneath the crossbar with the assistance of electronic devices and at the same time assisting the referee in awarding a goal or not. The objective of goal-line technology (GLT) is not to replace the role of the officials, but rather to support them in their decision-making. The GLT must provide a clear indication as to whether the ball has fully crossed the line, and this information will serve to assist the referee in making their final decision.[2]
Compared to similar technology in other sports, goal-line technology is a relatively recent addition to association football, its integration having been opposed by the sport's authorities. In July 2012, the International Football Association Board (IFAB) officially approved the use of goal-line technology, amending the Laws of the Game to permit (but not require) its use. Due to its expense, goal-line technology is only used at the highest levels of the game. Goal-line technology is currently used in the top European domestic leagues and at major international competitions such as, since 2014, the men's and women's FIFA World Cups.[3][4][5][6]