The user interface will be built by static and dynamic elements. The simple elements like UILabel, UIButton, UITextfield, UITextView, UIScrollView, etc are mostly not reuseable by their own and made to present static elements, while UITableView and UICollectionView is built in mind to present reusable content efficiently. They can handle 1000 of cells and items with high performance if you fulfill some simple rules. You can find an article about smooth scrolling in the resources.
The interface is based on a Model-View-Controller design pattern, where the interface can be built using the Interface Builder without any code. Then you can connect and add the code for its corresponding view controller.
Introduced in iOS 5, Storyboards are an exciting feature that save time building user interfaces for your apps. It allows you to prototype and design multiple view controller views within one file, which could be a blessing and a curse. For smaller projects, it’s more than ideal, but working with multiple people or with more than a couple of view controllers, it can be a real pain.
A constraint-based approach that allows you to build user interfaces that dynamically respond to both internal and external changes. Auto layout is not as difficult as some developers thought. Once you understand the basics, you will be able to use auto layout to create complex user interfaces for all types of iOS devices.
