Root is nicely protected

When you install Ubuntu 8.1, it will ask for a default username and a password for that username. It will then proceed to give all the administrative rights to that user. Whenever you want to perform some admin tasks, you can precede the command with "sudo". It will then prompt you for the password for the main username. On giving that, the command following sudo will be executed with administrative rights.

However that does NOT mean that such a user is the "root". The "root" is a special user who is sometimes; though rarely, needed. In the default Desktop version of Ubuntu 8.1 you cannot set the password of the root directly. However the main user can morph into the root using a terminal window.

Just give the following command:

sudo bash

It will ask for your password. Give the password that you had set for the default username. That is it. You have now become the root for that session of the terminal.

I think this is a good policy because the "root" user can create havoc on a Linux system if you are not careful.

Read more here http://www.cyberciti.biz/faq/ubuntu-linux-root-password-default-password/