If you had been using Google's backup and sync, you recently - October, 2021, have been forced to move to the new Google Drive for Desktop that combines features of previous Google products.
Click the gear icon on the new Google Drive icon and choose preferences. Here you can choose options for Google Drive or for My Laptop. The Google Drive gives you the option to have a completely virtual drive with cloud only storage. When you open a file, it streams from online storage. Or you can choose to mirror that drive on your own PC or Mac.
The other option, My Laptop, requires actual folders on your computer. Select any folders on your computer to synchronize with backup folders in the cloud. Otherwise the two options are identical. Either way, your files will synchronize as you edit or add files from any device.
Compared to DropboxRead More.
The My Laptop option allows you to keep your file structure instead of moving files into a special folder. For example, Dropbox can synchronize files, allowing you to edit from any device with Dropbox installed. However, these file must be kept in a Dropbox folder.
If you are an IOS user of Microsoft products, Google Drive presents some challenges. If you would like to edit or read a Word document, say, on your IPhone, normally you can select the file to open from online storage. For example, you can select from Dropbox or OneDrive or many others. However, Google Drive is not an option. Fortunately, there is a work-around. In the online storage options list, choose "Files App" From there, you can reach Google Drive - but only the files that were stored in the dedicated Google Drive. You can't reach the files that you used the "My Laptop" option to synchronize.