What is Automatic Setup, and how does it work?
Apple's Automatic Setup feature began as an easier way for users to set up the Apple TV with "tap-to-set-up," which let you use your iPhone's sensors to quickly connect to your Apple TV and automatically enter in data like an Apple ID and Wi-Fi network. Since then, the feature has evolved and expanded to cover not only the Apple TV, but new iPhone, iPad, and Apple Watch models as well.
Automatic Setup is great because it lets users skip much of the form-filling present in older versions of setting up new devices — you shouldn't have to manually enter Wi-Fi network names and passwords, Apple IDs, or settings from previous devices. It's also proximity-based, keeping that data secure by requiring you to physically have both old and new devices in the same location.
Apple uses a slightly different method to automatically set up each device, depending on whether it's an iPhone or iPad, Apple Watch, or Apple TV.
How to use Automatic Setup to set up a new iPhone or iPad
You can use any current device running iOS 11 to set up a new iPhone or iPad by transferring the settings from your current device to your new device when in close physical proximity.
How to use Automatic Setup to set up a new Apple Watch
There are a few ways to pair your Apple Watch to your iPhone, depending on what makes the most sense for your needs. Automatic Setup lets you quickly sync your Apple Watch's internal signifiers to your iPhone and get everything set up.
How to use Automatic Setup to set up a new Apple TV
Once you get your new Apple TV, you'll have to set it up from scratch. Apple offers two different ways of initializing your Apple TV: Set Up With Device, and Set Up Manually. If you don't have your device handy, Rene has a great how-to on manually setting up your Apple TV; otherwise, the easiest and best way is to use your iPhone, iPad, or iPod touch.