Right after the installation of every linux distro, there are a lot of groups (view at /etc/groups).

For example: root, wheel, disk, games, users, lpr

what is the meanings of these groups?

for example: lpr is for the printer. Adding an user to this group allow that user to use the printer.

if we have K3b, usually there is a group named "burn", "burning" or similar.
Users of this group can use the burner and so on......

but there are a lot of groups that are somehow "secret"

Someone can tell me a link, website or post the meaning of the system default group?

thanks, thanks, thanks a lot!!!!!!!!!!!!

Your best bet would be to look in the website for your distro. Some of the groups like 'wheel' and 'audio' are standard but others like 'fileshare' may be distro specific.

Also, look in /usr/share for PAM documentation. Logins and group access are probably controlled there.

Here is a similar LQ thread: http://www.linuxquestions.org/questi...hreadid=220972

After seeing this thread, I found a listing of default groups in Arch Linux. It must be somewhat distro specific though, or perhaps dependent on what software is installed, because there are a number of groups in my SLES10 server that aren't listed here. But it's a good start:

https://wiki.archlinux.org/index.php/Users_and_Groups