Choose to set up iCloud, and you'll also be asked whether you'd like to enable iCloud backups for your device. If you do so, you can have your device back up all essential settings to your iCloud account; if you ever need to restore, you can do so over Wi-Fi without needing a computer. (Of course, if you'd rather back up to your computer, you can always elect to have iTunes back up your device.)
Your device also prompts you to set up Touch ID using your fingerprint, along with entering a passcode to protect it from potential thieves or snoops. If you'd rather not set one, you can skip this step.
Your iPhone will also ask if you want to enable Siri, Apple's personal voice assistant.
You can toggle Siri on or off from this initial setup screen, but you can always change your preferences from the Settings app at a later date.
Because the iPhone 6 and 6 Plus screens are larger than their past brethren, Apple has included a new feature called Display Zoom that you can opt to turn on during the setup process. Display Zoom basically does what it says on the tin: It scales up the pixels on your device so that everything's just a bit larger; text, touch targets, buttons, and your keyboard all increase in size.
You can preview what Display Zoom looks like before deciding whether to enable it or not; if you choose not to, you can always turn it on (or off) at a later time by going to Settings > Display & Brightness > Display Zoom.
Once you finish the setup process, you see a screen asking if your device can automatically send diagnostic and usage information to Apple and third-party developers to "help Apple improve its products and services."
Choose Automatically Send or Don't Send, and then tap Next.
Congratulations! You've answered all the setup questions and you're ready to begin using your iPhone. At this point you may also be prompted to download your free copies of Apple's App Store apps.
Get started with your iPhone 6 and 6 Plus
Now that your device is up and running, here are a few quick pointers.
Tweak your settings: Most of the underlying system information for your new iPhone — network settings, Mail, sounds, messages, restrictions, wallpaper, and more — is kept in the Settings app. As such, it's a good place to start when you're first getting acquainted with your device.
Set up iTunes sync: If you didn't restore from an older iOS backup, you won't have any music, video, podcasts, photos, or books on your iPhone. You can remedy that by connecting it with your iTunes library: Just plug your device into your computer via its included USB cable. (Once you've completed this initial sync, you can also set up wireless local syncing; check out our guide for more information.)
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