Each user belongs to one or more groups. The only real importance of
group relationships pertains to file permissions.
Group information is stored in /etc/groups in the format:
The password field is sometimes used to set a passwrod on group access. This
is seldom necessary. To protect users from changing to privelegde groups
with the newgroup command, set the password field to *.
Users should not be assigned (belong to) to groups like: bin, mail, sys,
... They are for system file permissions.
to add a group, add a member to a group, delete a group, or remove a member
from a group edit the /etc/group file