Microsoft is not kidding around when it says it wants Office to be everywhere. While the company could (and has in the past) only offered users the ability to sync with its OneDrive cloud storage program, it now offers a built-in ability to sync with Google Drive and Dropbox.
From The Verge:
It’s a pretty simple tool that lets you see and open any Office files you have saved in your Drive, and any local files that you’re working on can be saved directly to Drive as well.
It’s not wildly different than what you’d get if you just installed the standard Google Drive app to your computer — but if you don’t want to sync your Drive locally, this plug-in should make it easier to interact with Office files that you have in Drive or want to save there. If for some reason you’re a Drive loyalist who also loves using Office, this tool just might make your life easier; it should be available to install today.