There are more carbon compounds than there are compounds of all other elements combined. The study of carbon compounds, both natural and synthetic, is called organic chemistry. Plastics, foods, textiles, and many other common substances contain carbon.
In a nutshell, Google Backup and Sync is a combination of Google Drive and Google Photos. There is no need to use two separate apps, as you can do it all with a single tool. Though, it is missing an easy way to restore the backup.
Syncing your Gmail account to your Google Android device is the easiest way to maintain your contacts. It allows you to have a backup of all of the contacts in the device stored within the Gmail system.