<P> In computing, the superuser is a special user account used for system administration . Depending on the operating system (OS), the actual name of this account might be root, administrator, admin or supervisor . In some cases, the actual name of the account is not the determining factor; on Unix - like systems, for example, the user with a user identifier (UID) of zero is the superuser, regardless of the name of that account; and in systems which implement a role based security model, any user with the role of superuser (or its synonyms) can carry out all actions of the superuser account . The principle of least privilege recommends that most users and applications run under an ordinary account to perform their work, as a superuser account is capable of making unrestricted, potentially adverse, system - wide changes . </P> <P> In Unix - like computer OSes, root is the conventional name of the user who has all rights or permissions (to all files and programs) in all modes (single - or multi-user). Alternative names include baron in BeOS and avatar on some Unix variants . BSD often provides a toor ("root" written backward) account in addition to a root account . Regardless of the name, the superuser always has a user ID of 0 . The root user can do many things an ordinary user cannot, such as changing the ownership of files and binding to network ports numbered below 1024 . </P> <P> The name root may have originated because root is the only user account with permission to modify the root directory of a Unix system . This directory was originally considered to be root's home directory, but the UNIX Filesystem Hierarchy Standard now recommends that root's home be at / root . The first process bootstrapped in a Unix - like system, usually called init, runs with root privileges . It spawns all other processes directly or indirectly, which inherit their parents' privileges . Only a process running as root is allowed to change its user ID to that of another user; once it's done so, there is no way back . Doing so is sometimes called dropping root privileges and is often done as a security measure to limit the damage from possible contamination of the process . Another case is login and other programs that ask users for credentials and in case of successful authentication allow them to run programs with privileges of their accounts . </P>

What is the administrator equivalent account in linux called