Use the USB cable that came with your device.
 Do so if it doesn't launch automatically when your device is connected., An icon for your iPhone will appear at the top of the screen once iTunes recognizes it., It's in the "Automatically Back Up" section.

If you wish to back up your passwords, Homekit data, or Health and Activity data, you will need to check the box that says "Encrypt iPhone backup" and create a memorable password.
 It's in the right pane of the window under the "Manually Back Up and Restore" section.

Wait for iTunes to finish backing up and saving your data. The process may take up to several minutes to complete depending on the amount of data you have stored on your iPhone.
 The eject button is located to the right of your iPhone's name. Disconnect your phone by unplugging the USB cord., Do so by holding the lock button on the right-top or upper-right side of your phone's housing until "slide to power off" appears on the screen, then swipe "slide to power off" to the right.

If your iPhone uses a SIM card, remove the SIM card from the older iPhone, and insert it into the new iPhone.
 Do so by pressing the lock button., You will be asked to select your country, language, location services preferences, and more., It will be listed as one of the options to set up or restore your new device., Use the cable that came with your new device as it may be different (lighting connector instead of 30-pin connector).

iTunes will recognize the new device and display “Welcome to your new iPhone.”

, Select the most recent backup from the dropdown menu., iTunes will begin to transfer data from iTunes to your new iPhone.

Wait for your new iPhone to restart. After your iPhone reboots, it will be ready for use.
Connect your old iPhone to a computer.
Open iTunes.
Click on your iPhone.
Click the button next to "This computer".
Click on Back Up Now.
Click the Eject button, and then disconnect your phone from the computer.
Power off your old iPhone.
Power on your new iPhone.
Walk through the initial iPhone setup process.
Tap Restore from iTunes backup.
Connect your new iPhone to the same computer.
Click on the “Restore from this backup” radio button.
Click on Continue.
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