With iCloud or iTunes, you can backup iPhone files to computer
. Personally, I prefer to use iCloud because it can do the backup more specifically. Go to Settings>iCloud and then scroll down to Backup.Here you can turn backups on and initiate a new backup immediately. If this is your first iCloud backup it might take a while to complete. Once the backup is complete, though, your iPhone will automatically backup when idle for an extended period of time and on an active wi-fi network.