Can Linux be shut down by the root user?
The root account is a built-in account with administrative priviledges in Linux. An admin user is usually a different account with priviledges to do certain administrative tasks. The admin user account is not a built-in account and must be added and managed appropriately. The root account comes with the system.
A "root" user has the power to do anything on a Linux system. A "normal user" will be assigned some of these capabilities based on what group they are in, but is generally prevented from running any commands that may affect the system outside of their home directory. Users can be granted "sudo" rights, which allows them to run the sudo command and temporarily be granted root privileges.