File and Directory permission management

File and Directory access authority: Descriptions on file / directory access authority. I will explain how to check the set access privilege and how to view the displayed contents.
Symbolic notation and numerical notation of access right (permission): Explanation of symbolic notation and numerical notation of access permission (permission) of file / directory.
Change of access right (permission) - chmod: How to change file / directory access rights (permissions). Explains how to use chmod in detail.
Change ownership and groups of files and directories - chown: How to change file/directory ownership and groups, explaining the detailed usage of chown.
Changing file and directory groups - chgrp: How to change groups of files and directories, and how to use the chgrp command.
SUID (Set User ID) - Special access rights: Description of a special access right called SUID (Set User ID).
SGID (Set Group ID) - Special access rights: Description of a special access right called SGID (Set Group ID).
Sticky Bit - Special Access Rights: Sticky Bit - A description of special access rights.
Default access rights - umask: Describes the default access rights for files and directories, explains the umask value and how to set it.