This exercise is priceless for core strength and stability. It’s obviously a leg exercise, but it’s also good for keeping your stomach and back muscles strong, because you cannot lean forward too much, it’ll keep you from injuring yourself in other lifts.
Start by snatching the bar or taking it off a rack with a wide grip. Squat as low as you can without relaxing. Ideally your thights should be just below parallel to the floor. If you have flexiblity problem, try to go a bit lower each time.