Like an MS-DOS prompt window, the Unix shell is a command interpreter that lets you issue and execute commands. By means of the shell, you use and control your system. If you're accustomed to the point-and-click world of graphical user interfaces, you may question the value of learning to use the Linux shell. Many users initially find the shell cumbersome, and some retreat to the familiar comfort of the graphical user interface (GUI), avoiding the shell whenever possible. However, as this chapter explains, the shell unlocks the true power of Linux.
 Most of the statements in this chapter are true of Linux generally, rather than merely true of Red Hat Enterprise Linux WS and Fedora Core. However, in this chapter, I use the term Linux as a concise way of referring to Red Hat Enterprise Linux WS and Fedora Core.