Root

From TheLinuxVault

The root user is the main administrative user on a Linux (or Unix) system. Many modern distributions do not allow a user to sign in as root, because it creates a security vulnerability. Instead, to use administrative applications, a user uses a utility (such as sudo). This requires adding the word "sudo" before a command.

Example

sudo echo 1 > new.txt

You may need to look up how to use administrative applications on your distribution.

[edit] File browser as root

On systems that use the nautilus file browser, the command would be:

gksu nautilus

[edit] Becoming root (not as "sudo") when root is disabled

If for some reason you need to be root (some commands cannot be done with only sudo), and the root user is disabled, but you have sudo access (such as on Ubuntu) you do not need to enable the root account to do things as root. Simply open a terminal and use the command:

sudo su

Not many commands require this. (the command "su" changes to the root user, and "sudo" allows commands to be run as root)