Unbox your iPhone and turn it on by pressing the On/Off switch. A welcome screen greets you, displaying a Slide To Set Up slider that rotates between different languages. (If you need quick access to your device's IMEI or ICCID number without setting up the phone, you can tap the information button [represented by a lowercase i] located directly above the slider.)

Once you begin the activation process, you're asked to pick your language and country, and whether you'd like to enable Location Services. This allows Apple apps (and third-party apps) to access your location via Wi-Fi networks and your GPS (Global Positioning System) location. Your iPhone then checks for any Wi-Fi networks in the area that your phone can connect to; if there aren't any, or if you'd rather use your cellular service, just tap the Next button.

From here, you can set up your device as a brand-new phone or, if you're upgrading from an old iPhone, you can restore your data from an iCloud or iTunes backup.

Restore from an iCloud backup

If you have an iCloud account and have backed up a previous iPhone or iPod touch incarnation using iCloud's Backup feature, you can use this backup to restore your data to your new iPhone (though you'll need to be on a Wi-Fi network to do so). To restore your data, sign in to your iCloud account; agree to Apple's terms and conditions; and then choose which backup file you'd like to use, and tap the blue Restore button in the top right corner of the screen. (Depending on the speed of your Wi-Fi connection, this process can take anywhere from a few minutes to a few hours.)