Day -1 

1. What is Application Life cycle (App states)
2. What is viewcontroller life cycle and explain the methods in detail
3. What  is App Delegate and Methods
4. Explain did finish launching option and application terminate method
5. What is Scene Delegate
6. What is UIWindow?
7. What is UIResponder?
8. What is Viewcontroller? 
9. class ViewController: UIViewController  { } - Explain this syntax
10. What is Override -  override func viewWillAppear(_ animated: Bool) { } - Explain this syntax