Mounting a camera onto the screw on top of a tripod head is time consuming. Doing it in the dark when your hands are cold is annoying. Once the camera is mounted, if you flop the camera over to the side to take a vertical photo, the camera tries to rotate on the screw. To provide a solution, all kinds of “quick release systems” have been created. Some of them work quite well, some not so well. Most systems have a weakness of one kind or another.
One system has become the defacto standard for serious photographers. It is arguably the best. If you are tired of the nuisance of screwing your camera onto your tripod head, or if you’ve grown weary with the problems created by an inferior quick release system, it is time for a change. Go here.