During NFL games the commentators often talk about the play design. One thing that comes up a lot is the formation at the time of snap and quarterback's play readability. The quarterback could be under the centre and pick up the football from his centre. Or he could be standing few feet behind him and catch the ball out of the shotgun. The commentators also mention how rookie QBs are not used to playing under the centre and that some of the struggle to transit from almost always playing out of the shotgun.
So I'm interested to know what are the strategical and performance differences of these configurations?