User
How to add user to the system and setting the password to that user and modify the user details and add user to specific group
Group
How to create group and add a group to specific user

Before using the command make sure that you logged as a root user

The useradd command is used to add or create so many user to the system

useradd lalitha

lalitha is a user add to the system

cat /etc/paaswd

it display the user id ,home directory and username of all created user

if you want to see a specific user id, home directory etc...

you have to give

id lalitha

it give specific user id, home directory , user name and group name also

The set passwd is used to set a password to a specific user

passwd lalitha

it first ask to set the password and again it ask to retype if it display authentication successful then the password is setup for a specific user.

The usermod -d is used to change the home directory of the user

 usermod -d /home/newjohn john

the usermod -aG is used to add the user to specific group

usermod -aG techdev lalitha

userdel is used to delete the user from the system

userdel lalitha

ADDING OR CREATING A GROUP

the groupadd command is used to add or create group in the system

groupadd devtech

cat /etc/group

it display the group name, id of all

to check the details of specific group

id group name is used to display specific group id,name etc..

id devtech

how to add a user to specific group

you already saw one method that is usermod -aG group name username another one is

chgrp group name username

groupdel is used to delete a group from the system

groupdel devtech

its delete or remove the group

that's all we will meet soon.....

bye.....

Guide to Basic User Management Commands