Google Drive is a web-based file synchronization service launched by Google on 24-April-2012. It replaced Google Docs and provides 15 GB of free storage (shared amongst Gmail, Google Drive, and Google+ Photos), with the option to rent more.
Google Drive offers a client for PC and Mac that automatically syncs files in the background that are placed in a special folder (similar to Dropbox).
Questions here on Super User should be concerned primarily with the client app, local storage and file synchronization.
There is also a web application that allows managing your stored files as well as a number of office productivity apps (Google Documents, Google Spreadsheets, Google Presentations). Questions about that aspect of the service are off-topic here and should be asked at Web Applications.
There are also Android and iOS (iPhone/iPad) clients that allow for automatic synchronization to/from local storage on your device.
For questions specific to...
- the web application, please visit Web Applications.
- the iOS app, please visit Ask Different. (May also be appropriate for the Mac client.)
- the Android app, please visit Android Enthusiasts.