free book on UNIX/Linux System Administration This subchapter also discusses the logout command and the importance of always logging out from a running system. In particular, this subchapter discusses choosing the system and terminal type, rare options that you might encounter. This subchapter furthers the discussion login in more detail than the previous subchapter�s introduction, including special cases and solutions to common problems. On a multi-user UNIX or Linux system, such as a web server, you will need to login. You can just start your terminal emulator (see previous subchapter). On a personal computer or workstation you probably don�t need to login. This subchapter looks at login and logout, a pair of UNIX (and Linux) commands.