Explain the 3 kinds of file permissions under Linux.

• A. Owner, Member, Guest
• B. User, Group, Others
• C. Admin, User, Root
• D. Primary, Secondary, Tertiary

Answer: (B)

In Linux, access to a file or directory is controlled for three user classes: the owner of the item, the group associated with it, and all other users. Each class can have read, write, and execute permissions, which determine what actions you can take. You can see these permissions in a long directory listing, which shows a pattern like rwxr-xr--: the first trio applies to the owner, the second to the group, and the third to others. Permissions are managed with chmod to set the read/write/execute bits, while chown changes the owner and chgrp changes the group. Understanding these three classes explains how access is granted or restricted for different users, which is why the three kinds are owner (the user who owns the file), group, and others.