Google has recently discontinued their standard Google Drive desktop application and replaced it with two new applications: Drive File Stream and Backup and Sync.
Backup and Sync
With Backup and Sync, you can choose to backup any folder on your computer such as your Desktop, Documents, and Photos. You can also backup data on attached devices such as external hard drives, or SD cards. To get started, you will need to install the application. Google has some great documentation if you need additional help on setting up specific settings.
Drive File Stream
This is the IMT recommended application that makes your entire Google Drive available on your Mac or PC while using no hard drive space. As long as you are connected to the internet you’ll be able to open and edit your Google Drive files right from your desktop. You are essentially streaming files, just like you would stream video on YouTube or Netflix.
You can also choose to keep certain files or folders offline for editing while you are not connected to the internet. The next time you connect, those changes will be synced to Google Drive on the web, and your work will be saved there.
Drive File Stream is the only application that can give you access to Google Team Drives on your local computer.
Using Both Drive File Stream and Backup and Sync
You can use both Drive File Stream and Backup and Sync together on the same computer. You’ll want to turn off the Google Drive feature in Backup and Sync so your computer doesn't sync those files twice because File Stream is already syncing those files for you.