Red > Green > Refactor > Red

cycle is based on desire

Views and View Controllers ; difference

just have resources

or

mange the resources

Views

  • Manage Your Application’s Visual Content

View Controllers

  • Manage Views
  • Manage Resources
  • Respond to Events
  • Coordinate with Other Controllers
  • Often Work with Containers
  • May Be Presented by Other View Controllers

reference

developer.apple.com

developer.apple.com