daengbo at gmail.com
Sun Nov 22 12:08:55 UTC 2009
1) The root user has his own group (as does every user), and has full
access to everything on the machine. The adm group is for some
services. The admin group allows users to use sudo with a password.
The sudo group allows users to use sudo with no password requires.
The /etc/group file is about thirty years old, and carries some
redundancy due to various separate projects working together. Read the
following link, especially section 8.9.
2) The Unix filesystem has a long history and the Linux filesystem is
a derivative of it. Please read:
More information about the ubuntu-doc