The aim of this technology is to assist the referees in goal line decision making. The technology should clearly determine if the ball has passed the goal line, using which the referees will take the decision. Currently, Hawk-eye and GoalRef are granted licenses by FIFA.
Unlike Cricket, if the referees err with the Goal Line technology; it will spell a disaster as the popularity of this sport spans the entire world across viewers, communities and sporting associations.
In my opinion, any sport should be kept miles away from any sort of technological interference. Allowing technology to play it's part spoils the fun. We have evolved in this age and the commonest of sense tells us that we should allow this. But it takes away the human factor out of the sport. The referees in the 19th century did a far better job in referring in every single sport. These days news comes out related to betting, match fixing and this has only tarnished the image of the sport on a whole.
For information on how this technology will be used in the matches, refer the below video.