The highest authority or privilege given to a user working with an operating system or other control program. A person with root level access is called an "administrator," "root user" or "superuser."
High and Low at the Same Time
While root level access is considered a "high" privilege level for the user, it is at the same time considered "low" level access to the system. See
tree,
root directory,
root server,
rooting,
privilege and
administrator.