can not find "system"

The new Unity Interface changed everything, and the old method of finding tools is now gone. Many people are less than thrilled about this. However, you can just search for the app directly now.

Some info on terminology.
https://help.ubuntu.com/11.04/ubuntu-help/index.html
http://askubuntu.com/questions/10228/whats-the-right-terminology-for-unitys-ui-elements/19166#19166

System settings can be found in the panel in the right top corner or in launcher left hand side.
CLI:
gnome-control-center

Admin is a group where usually the first user, which installed the system, is in.
CLI:
groups

Terminal.
http://library.gnome.org/users/gnome-terminal/stable/gnome-terminal-get-started.html.en

A user gains advanced privileges through 'sudo'.
https://help.ubuntu.com/community/RootSudo

Lets say a user wants to install some package:
sudo apt-get install <package>
https://help.ubuntu.com/community/AptGet/Howto

The GUI pops up an authentication dialog.
https://help.ubuntu.com/community/SoftwareCenterFAQ
https://help.ubuntu.com/community/SynapticHowto

in version 10.10 and prior versions of ubuntu, you'll find the following across the top of the screen "applications, places, system".

this is the system everyone is referring to. click on system and other menu items, such as preferences and administration, appear.

if you're using version 11.04 or later, you can click on the ubuntu logo on the top left of the screen, not the red thing but the black and white thing, on the left of the screen to open the "dash" where you can type such words as "display", "hardware driver" that appear under system>administration

@sam
at least unity isn't like microshaft's crappy ribbon. EEEK! EEEEW!
i think it's supposed to provide a PIM-like environment

Thank you very much, I had to reinstall Ubuntu and accedentily loaded and old one and it has the menu at the top, I really apreciate the help.

still cant find in 11.10

That is because "System" is gone now. The User Interface is radically changed with Unity. You now search for apps directly. Or, you hold on 10.04, like many of us have.