I add a “align” constraint, but Xcode add a “pin” constraint autolayout
问题 When we add constraints, we have the choice between "Align" button in the auto layout toolbar or "Pin" button. In my storyboard, if I add a new alignment constraint "Bottom edges" between a scrollview and his container. The icon of this constraint is 2 squares and a line. But after, in the list of constraints of my scrollview, the icon is different : The icon is a "Pin" icon. I don't understand why. One more question, I think it's related : what is the difference between "Align bottom" and