What is sudo?

Answer 1

sudo is a Linux command used to execute programs as the root, or "super user." sudo is a shortening of "super user do." One uses sudo when they need to run a command or program as root, but do not wish to log out or switch their entire shell to root privileges (like they could do with the su command). The file sudoers defines per user or per group what commands can be run with sudo. This file is edited with the command visudoers

Answer 2

sudo in Linux enables normal user to run superuser(or other user)command in Linux.

The configuration is provided in /etc/sudoers file.

The real and effective uid and gid are set to match those of the target user as specified in the passwd file. If the invoking user is root or if the target user is the same as the invoking user, no password is required. Otherwise, sudo requires that users authenticate themselves with a password.