Introduction to Auto Layout for iOS and OS X

If your application has a user interface, then this session is for you. iOS 6 adopts OS X Lion's powerful constraint-based layout engine, making it easy to design a flexible user interface that responds dynamically to layout changes such as rotation and varying status bar heights. This session will cover the basic concepts, IB support, and API you'll need to get started using auto layout.

WWDC 2012 - Session 202 - iOS, macOS