Sudoer is the functionality of the Linux system that can be used by an administrator to provide administrative access to a trusted regular user, without actually sharing the root user's password. The administrator simply needs to add the regular user in the sudoers list.
Once a user has been added to the sudoers list, they can execute any administrative command by preceding it with sudo. Then the user would be asked to enter their own password. After this, the administrative command would be executed the same way as by the root user.