If you notice, you will find that Ubuntu never asks for a root password while installing. The thing is, root account disabled as default. This is not true in almost every case. So how can we enable it ?. sudo can do the trick. It means ” Super User DO “.If you are not a power user, you don’t need to activate root account. If you are ever asked to type a root privileged command, you could use sudo. To run using sudo
$ sudo < command to execute >
This will prompt for a user password.
If you are someone having lots of fun in terminal, activate the master.
$ sudo passwd
This will prompt for new root password and once you confirm it, you can start using root account. There is another option, type $ sudo -i for a root console.
Disable root by
$ sudo passwd -l root
For more administrative task use visudo, a privileged command which can change the power of users and groups.