When the club head hits the ball the club head is rotating around the center of gravity axis which is in the middle of the club. When the head rotates and hits the ball the gear effect comes into play. The gear effect is thinking of the golf ball as one gear and the face of the driver as another gear. So as you hit the ball if you catch it on the toe then the ball will slice and have side spin moving to the right of the hole and if on the heel of the driver you will hook it so the ball curves to the left of the hole. So if you hit it right inside the center of gravity on the club then the ball should go straight. There is also a second curve to the club not just horizontal but vertical. The vertical curve defines the launch angle of the ball of the face of the club. Again the center of gravity is the key spot to hit it. If you hit it to high up on the club face then it will pop up into the air, and to far down on the club face then it will be forced into the ground a few meters in front of you.