root
also: superuser, administrator, UID 0
The superuser account (UID 0) with unrestricted permissions to modify any file, run any command, and manage the entire Linux system. The administrative account with the highest privilege level.
root is the default administrative user on Linux systems, distinguished by user ID (UID) 0. Unlike regular users who have limited permissions, root can read, write, and execute any file, kill any process, and modify system configuration without restrictions.
You can become root temporarily using sudo (execute a command with root privileges) or su (switch user to root). For example, sudo apt update allows a regular user to update packages, while sudo reboot lets them restart the system—actions normally restricted to root.
The root user's home directory is typically /root, and its shell is often /bin/bash. The root account is displayed in prompts with a # symbol instead of $.
Best practice is to avoid logging in directly as root and instead grant specific permissions to regular users via sudo, reducing the risk of accidental system damage or security breaches.