You can automatically back up the following items to your Google account:
Not all apps back up data automatically. Check with the app developer.
To automatically back up to Google Drive:
To back up other files that aren't automatically backed up, like attachments or downloads:
On your phone:
To learn about managing phone backups from a computer, read Google's help.
When you add your Google account to a phone, photos, contacts, settings and app data that you previously backed up to that account are restored onto the phone.