Good tip from Patrick Holland:
iCloud is a free account (more on that later) that’s tied to your Apple ID and can back up your iPhone. However, it doesn’t back up everything on your phone.
Apps, for example. Is there a better way? Yes, but more complicated than the automatic iCloud backup.
Remember iTunes? Good ol’ iTunes. If you’re running MacOS Mojave (10.14 or earlier) or you’re on a PC, you can just plug your phone into your computer and back it up to iTunes instead of using iCloud.