What is Auto Layout?
Auto Layout is a constraint-based layout system. It was introduced with Xcode 6 Beta. It allows developer to create an adaptive UI for the apps that responds appropriately to changes in screen size and device orientation.
Auto Layout dynamically calculates the size and position of all the views in your view hierarchy, based on constraints placed on those views.
Why Auto Layout?
Today we have lots of variants available of iPhone and iPad in size in market. So, the user...