Google Drive and Google Photos are excellent tools for backing up your document and photos. With that said, they can only back up files stored in the Google Drive or Google Photos folder, making backing up existing documents a bit difficult.
To save the hassle, Google has introduced a new Backup and Sync app for Window and Mac. It links to your Google Account and automatically backs up folders selected by the user. Once installed, Backup and Sync will replace the Google Drive and Google Photos app. You can manage storage for both under one settings panel.
Eager to try it out? Download it from Google.