How do I transfer content from an old iPhone to a new iPhone?

We recommend using iTunes following these instructions from Apple (skip the iCloud part and scroll down to the iTunes instructions):

https://support.apple.com/en-us/HT201269

How do I do this if I'm on Windows?

The process is pretty simple. Follow the following instructions:

1. First, download iTunes from this link. This will direct you to the Microsoft Store. Click on the blue "Get" button.
2. You'll be prompted to go to the Microsoft Store. You don't have to sign into Microsoft but that's an option that's available to you. Once it is downloaded, you'll be able to launch iTunes.
3. You will need to log in with your Apple ID.
4. Next, open iTunes. It should be very similar to the Mac version. You can now connect your device to your computer's USB port, and run a backup that you can use to later transfer files to a new device (using "Transfer purchases").
    
5. Refer to the link at the top for instructions on how to perform a backup. You will be redirected to a page that explains how to do this on a Mac - as mentioned earlier, the Mac and Windows versions of iTunes are very similar and you should be able to do the same things in both applications.