Upon the setup of a new Debian system, a default root account is created. The root user has full system access and privileges and can pretty much do anything on the system that a regular user can't. Some of the tasks confined only to the root user include installing, updating, upgrading and deleting software packages, modifying configuration files, starting and stopping system services and performing server shutdown and reboots. The root user is powerful, but extremely dangerous because actions performed cannot be undone. Some commands, if issued, can render the system unusable.