Superuser

The root account or superuser account is the user account that needs to be created during the installation of an operating system and is equipped with most extensive privileges.

This account is not intended for everyday use of the system, but only for specific administrative tasks, because it is associated with extensive risks.

Unix-like systems

On Unix-like systems, each user account is associated with a number: the so-called "UID " (User ID). The first user account on each system has the UID 0 and has historical Unix systems all rights over the resources of the system. Because this account is necessary for the installation of the computer and should therefore show all files and directories from this account, one can speak here of a " root " (English root). After installation is complete, you can account for this administration ( Administration) use of the system. In order to work as root you either login or corresponding change to the Unix shell using the su command the identity.

Modern Unix systems such as Solaris implement fine-grained rights systems. On such systems, means obtaining the UID 0 not necessarily the acquisition of all rights.

The user has the root privileges are the only user on a Unix computer unrestricted rights, which is characterized in particular in file management (file rights, etc.) and use of system resources (memory, devices). A special place is given to the root also in the management of kernel and process control: This allows the root change all processes at will, thus, for example, restart the computer. For a kernel that supports dynamically loadable modules, root can act indirectly to the kernel space to the next level.

If a malicious cracker to find out the root user password, so this is therefore completely compromised. To hide their own presence on the system administrator following a successful attack, attackers use so-called rootkits.

Usually, the user root prompt from the other user differs by a final hash (#) instead of a dollar sign ($). System administrators speak in this case of a root prompt.

Mac OS X

When you install Mac OS X account for the System Administrator root is created with the name and one for the admin with selectable name. With Mac OS X Server, both accounts get the same password during the normal OS X root account a password and receives will be blocked. The Admin is not just some denied what is possible for root, but also vice versa.

Debian and Ubuntu

When installing Debian can also be to achieve that, under the Debian -based on Ubuntu there is the normal installation not even have the opportunity to do otherwise. For security reasons, the user group admin has there but no further permissions to run as sudo. Thus, their members can temporarily gain the superuser. Typically, sudo is invoked automatically when the superuser is required. However, it is by means of the command "sudo passwd" at any time permanently unlock the root account, where you refer to it a valid password.

Toor

Toor is the backwards written word for root and constitutes an alternative root, especially on BSD derivatives. The account also has the UID 0, but differs by a different configuration, mainly by a different shell of the root account.

Usually has an account ( usually root ) an extensive shell ( such as bash or zsh ), while the other account (usually toor ) a minimal shell has only. The intent is to keep available an account with system administration skills, even if the default shell of an account can not be started ( for example, if the partition on which the shell is, can not be mounted). " toor " is also the password for the root account in the known Backtrack distributions.

Microsoft

While MS -DOS and the original Windows Millennium Edition to only allowed a single user account, which inevitably had all permissions, Windows NT has supported multiple user accounts with different privileges. The user account root account here has the user name "Administrator". However, there is another account with higher privileges than those of the administrator. This is called " SYSTEM" is not normally used for administration of the computer. The user account named " Administrator " is on the new logon screen in Windows XP not visible by default, but it can still be used by the classic logon dialog, accessed either through the settings or by pressing Ctrl Alt Del on the login screen will. On Windows Server 2008 R2 also exists a user account named "Administrator", which must be set up at the first launch of the system after the installation, and just as with the current version Windows Server 2012 Standard / data center has the highest privileges.