The POSIX permissions are that each file or directory has an owner, group, and other with read, write, and executable bits, but only one user and one group. ACL are an extended set of permissions.
Linux SUID and SGID Permission
SUID ( Set User ID ) or SGID ( Set Group ID ) upon execution are Linux access rights flags that allow users to run an executable with the permissions of the executable’s owner or group respectively and to change behaviour in directories. They are often used to allow users on a computer system to
Linux Sticky bit permission
Sticky Bit is mainly used on folders in order to avoid deletion of a folder and it’s content by other users though they having write permissions on the folder contents. If Sticky bit is enabled on a folder, the folder contents are deleted by only owner who created them and the root user.
Linux Files and Directories Permissions
Each file and directory has three user based permission groups: Owner/User (u)- The Owner permissions apply only the owner of the file or directory, they will not impact the actions of other users. Group (g)- The Group permissions apply only to the group that has been assigned to the file or directory, they will not