Exit a login shell.

SYNTAX
logout [n]Returns a status of n to the shell&qt;&qt;s parent.

A login shell, is your topmost shell, and is started when you log in.

When you terminate a login shell (via the commands &qt;exit&qt;&qt;, &qt;logout,&qt;&qt; or the end of file [^D]), you are logged out completely.

Sub-Shells

A &qt;sub-shell&qt;&qt; is a shell created after login, either by loading a new shell or opening a window with a graphics interface. A sub-shell usually will not accept the command &qt;logout&qt;&qt; to terminate, you must use &qt;exit&qt;&qt; or ^D.
When you terminate a sub-shell, you are returned to the process or shell that created it.

Example (starting from a bash shell)
$ tcsh
&qt; # now in the tcsh shell
&qt; exit
$ # now back in the bash shell
$ logout