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.
Structure
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. Filenames seem practically unlimited in terms of length and permitted characters, though they may get altered on destination systems to which they are synced (e.g., with problematic characters replaced by underscores, and files with identical names getting suffixed numbers in parenthesis).
File metadata
Some metadata is kept on each file, and some of this is mapped onto corresponding metadata in the target operating system of a synced directory. Known fields include:
- Owner (Google account owning the file; it shows "me" if it is the currently-logged-in account)
- Datestamp last modified
- Datestamp last edited by me
- Datestamp last opened by me
- Quota used (file size; shows dashes if under 1 KB)
- File type
- Folder
- Drawing
- Image
- PDF file
- Presentation
- Document
- Spreadsheet
- Form
- Text document
- Video
- Table
- Compressed archive
- Probably a number of other file types
- "As Is" or "File" (used for unrecognized file types)
- File sharing status
