Every time you create an iOS project, it will likely include at least two .swift files: ViewController.swift and AppDelegate.swift. A ViewController.swift file connects to a scene in a storyboard and lets you write code that manages the user interface. Each time you add another view controller scene to the storyboard, you’ll likely need another ViewController.swift file (under a different name) to manage any user interface objects such as buttons, text fields, or switches.
Where a project can have multiple ViewController.swift files connected to different scenes ...
