A file system attribute used mainly for access control to file resources.
Many operating systems utilize the concept of file ownership to identify a specific system user as the owner of a file or directory. Where classes of users may be granted varying privileges for access to a file or directory (typically read, write, execute, or variations of those), the owner will have distinct permissions.
Useful links:
- File System Permissions in Wikipedia
- Understanding Linux File Permissions, Linux Foundation
- Filesystem Security from Brown University