Amazon WorkDocs vs Google Drive

Amazon WorkDocs
Amazon WorkDocs is a fully managed, secure enterprise storage and sharing service with strong administrative controls and feedback capabilities that improve user productivity. Users can comment on files, send them to others for feedback, and upload new versions without having to resort to emailing multiple versions of their files as attachments. Users can take advantage of these capabilities wherever they are, using the device of their choice, including PCs, Macs, and tablets.
Google Drive
Online file storage and syncing service working as a file system for other Google's services. Allows to sync files between all your computers and mobile devices or collaborate on files with your team and partners. Version control, OCR, powerful online viewer. Provides 5 GB free disk space. Google Drive free alternatives are: OneDrive, Box, Dropbox
Face to face in the news:

2017 - Google Drive gets a new Backup & Sync desktop app - a new advantage over Amazon WorkDocs

Google launched its new Backup and Sync app for both Mac and PC, which aims to help users more easily back up the files and photos on their computer. The utility is meant to replace the older Google Photos desktop app, as well as the Google Drive client applications. The new tool offers a simple user interface, where you’ll first sign into your Google account, then select the folders you want Google to continually back up to Google Drive. In addition to backing up files on your desktop computer, the new software also can be used to back up photos from USB-connected devices, like cameras, as well as SD cards. For business users Google is planning to release a new enterprise-focused solution called Drive File Stream, which will roll out to all G Suite users later this year.

2014 - Amazon launched enterprise file-sharing service Zocalo to catch up with Google Drive

Amazon targets Microsoft, Google and Box with their new enterprise file-sharing service Amazon Zocalo. It's based on Amazon Web Services and provides fully managed, secure document storage and sharing service designed specifically for the needs of the enterprise. Zocalo has centralized user management, and can also link to an existing Active Directory. This is a big deal, since one of the challenges with cloud-based document solutions such as Dropbox is the fact that permissions structures aren't granular enough to work in environments that have strict IT policies. Amazon also says that all documents are transmitted in encrypted form. Zocalo has client syncing apps for Windows and Mac for folder sync. You can also use Zocalo apps for iPad, Kindle Fire and Android tablets. The price is $5 per user per month for 200GB of storage.