Linux administrators have few options when it comes to adding a new user to the system, from filling up forms in distribution / desktop environment specific nice GUIs, to running through the command line with options and switches. For the geeky administratorss, there are always configuration files that can manually be edited just for this purpose.

The 2 most common programs used to add a user are, adduser and useradd. They are both quite similar (heck, they do the same thing anyway, which is to add user of course), but are a bit different in their interactivity level.