Root

Root access is used for administrative functions on a POSIX (aka Unix or Linux) based system. Just as the root of the filesystem is the place where all other folders are mounted, the term root is derived from the fact that all other accounts stem from this account,

How to gain root access
When using the access to the root account, you have full control over the system. It is a standard practice to limit this access as it is not necessary to have control over the entire system for most tasks. However, when root access is needed on a POSIX system, the user who elevates his/her permissions is generally asked for a password for authentication purposes.

Sudo
To gain temporary root access type sudo into your terminal: sudo (your command here)

Persistant Sudo
To gain root shell without setting a permanent password: sudo bash

Switching to the Root Account
To switch to the root account without authenticating with root credentials: sudo su

Enabling the Root Account login authentication
Enabling the root account is not recommended. This places a major security hole in your system when connected to a network. Malicious users will generally attempt to gain root access as a first attempt to log in. Do not set the password as "root"

To gain root access type the following into your terminal: sudo passwd root Your root is now enabled. You can now log in to XBMC as user "root" with the password you selected.
 * select a password

A friendly word on Security Risks
A lot of people would say that security on their home network is not important but I would like you to read this. When authenticated as the root user on a system, you have access to all account credentials which stem from the root user. If A user such as XBMC has access to your file shares, then the root user can gain access to those file shares. It is important to note that the root account bypasses security measures that are put in place to keep your information secure such as saved credit card and bank account information. The same people who write viruses would like to gain access to the root account on your XBMC computer.