useradd [options] account usermod [options] account userdel [-r] account (-r would delete the home directory)
Default values when creating a user stored under /etc/default/useradd
# useradd defaults file GROUP=100 HOME=/home INACTIVE=-1 EXPIRE= SHELL=/bin/bash SKEL=/etc/skel
/etc/skel contains the skeleton of the files in the home directory of any newly created account
/etc/login.defs file defines the site-specific configuration for the shadow password suite.
Disable an account : passwd -l account Enable an account : passwd -u account
groupadd [options] group groupmod [options] group groupdel [options] group
chfn : change finger info id : show your user and group ID’s groups : displays groups which you belong to finger account : get info about an account
pwck : verify integrity of password file grpck : verify integrity of group file
pwconv : creates shadow from passwd and an optionally existing shadow. pwunconv : creates passwd from passwd and shadow and then removes shadow. grpconv : creates gshadow from group and an optionally existing gshadow. grpunconv : creates group from group and gshadow and then removes gshadow.