adduser:-Command used to add user accounts.
chage:-Used to change the time the user's password will expire.
chfn:-Change a user's finger information
chsh:-Change a user's shell
chgrp:-Changes the group ownership of files.
chown:-Change the owner of file(s ) to another user.
gpasswd:-Used to administer the /etc/group file.
groupadd:-Create a new group.
grpconv:-Creates /etc/gshadow from the file /etc/group which converts to shadow passwords.
grpunconv:-Uses the files /etc/passwd and /etc/shadow to create /etc/passwd, then deletes /etc/shadow which converts from shadow
groupdel:-Delete a group
groupmod:-Modify a group
groups:-print the groups a user is in
grpck:-Verify the integrity of group files.
id:-Print group or user ID numbers for the specified user.
newgrp:-Allows a user to log in to a new group.
newusers:-Update and create new users in batch form.
passwd:-Used to update a user's password. The command "passwd username" will set the password for the given user.
pwconv:-Used to create the file /etc/shadow from the file /etc/passwd to convert to shadow passwords.
pwunconv:-Uses the files /etc/passwd and /etc/shadow to create /etc/passwd, then deletes /etc/shadow to convert from shadow passwords.
su:-run a shell with substitute user and group IDs
useradd:-Create a new user or update default new user information
userdel:-Delete a user account and their files from the system. The command "userdel -r newuser" will remove the user and deletes their home directory.
usermod:-Modify a user account.