Guide To Dynamic Loft
The loft of any golf club when it is placed on the ground is called static loft and in the case of your driver this is what is often printed on the sole. However, when you swing the golf club this loft effectively changes so that the loft of the clubface when it reaches the ball is often higher.
With the driver most players try to swing up through the ball which has the effect of adding dynamic loft to the driver. In addition the centre of gravity in a club head can also far back from the actual clubface, especially in the driver, causing the shaft to ‘bow’ as you approach the ball which also tilts the club head back and adds loft.