Linux Sudo User and Group Authorization with Visudo

If you want to provide special authorization to some users and/or groups in Linux derivatives, you can use the example below.

sudo visudo
username ALL=(ALL:ALL) ALL
# username user has the same privileges as the root user
username ALL=(ALL) NOPASSWD:ALL
# username user can perform all operations without typing a password
username ALL=(ALL) NOPASSWD: /sbin/reboot, /sbin/shutdown
# username user does not need to type a password for reboot and shutdown commands.
%usernamegroup ALL=(ALL:ALL) ALL
# users in the usernamegroup group have root privileges
%usernamegroup ALL=(ALL) NOPASSWD:ALL
# usernamedigoup users can perform transactions without typing a password