Google Drive
Google Drive is not the name of those self-driving cars that Google has unleashed on the streets. Rather, it is a "cloud-based" filesystem letting its users store files in a directory structure that is accessible from multiple places; through a web interface or through platform-specific clients which "sync" a user's Google Drive structure to a directory on their local system, where any changes at either end get replicated. There is also an API to use it in apps. As the access is done entirely through Google proprietary programs and sites, the low-level structure is hidden from the end user, but it is perhaps accomplished via a Google File System. The surface structure visible to the user is a typical hierarchical file system, starting at a user's home directory and allowing files and subdirectories (folders) within it.
