Below are the Excerpts of sudo from one of the books --- that need to briefed in layman terms 
with practical examples!
In addition, you can let a user run as another user on a given host. Such alternate users
are placed within parentheses before the commands. For example, if you want to give
george access to the beach host as the user mydns, you use the following:
george beach = (mydns) ALL
1) how will we practically let george act as mydns ?
By default sudo will deny access to all users, including the root. For this reason, the
default /etc/sudoers file sets full access for the root user to all commands. The ALL=(ALL)
ALL entry allows access by the root to all hosts as all users to all commands.
root ALL=(ALL) ALL
2) how will root be able to act as all users practically ?
To specify a group name, you prefix the group with a % sign, as in %mygroup. This
way, you can give the same access to a group of users. The /etc/sudoers file contains
samples for a %wheel group.
To give robert access on all hosts to the date command, you use
robert ALL=/usr/bin/date
3) how robert will be able to login to all hosts and howcome this SUDO configuration would be read by all of the systems on which robert would logon to execute the allowed command ???
Any LDAP|NIS relation to above texting ??? ||| And again, kindly text Practical examples and not MAY-Might-IIRC-be's ... !
with practical examples!In addition, you can let a user run as another user on a given host. Such alternate users
are placed within parentheses before the commands. For example, if you want to give
george access to the beach host as the user mydns, you use the following:
george beach = (mydns) ALL
1) how will we practically let george act as mydns ?
By default sudo will deny access to all users, including the root. For this reason, the
default /etc/sudoers file sets full access for the root user to all commands. The ALL=(ALL)
ALL entry allows access by the root to all hosts as all users to all commands.
root ALL=(ALL) ALL
2) how will root be able to act as all users practically ?
To specify a group name, you prefix the group with a % sign, as in %mygroup. This
way, you can give the same access to a group of users. The /etc/sudoers file contains
samples for a %wheel group.
To give robert access on all hosts to the date command, you use
robert ALL=/usr/bin/date
3) how robert will be able to login to all hosts and howcome this SUDO configuration would be read by all of the systems on which robert would logon to execute the allowed command ???
Any LDAP|NIS relation to above texting ??? ||| And again, kindly text Practical examples and not MAY-Might-IIRC-be's ... !
