Every operating system has an account to administer the resources of that system. In the case of CentOS Linux, this user account is known as root, very often called the superuser. The root account is the most privileged account in a Linux/Unix system. This account is used to carry out system administration tasks, such as managing user accounts and their passwords, managing software packages, modifying system files, and restarting system services. Extra caution must be taken while working as the root user as it has no security restrictions imposed on it. If the root account is compromised, then another person will have full administrative control of the system. The root account on Linux is equivalent to the local administrator account on Windows.
When you are logged in as the root user, the shell prompt displays the hash # symbol by convention...