As you learned in Chapter 1, directories and files are the heart of Unix; they contain things like setup information, configuration settings, programs, and options, as well as anything that you create. You access directories and files every time you type in a Unix command, and for this reason, you need to become familiar with the various things you can do with them.
Again in this chapter, the skills and commands we'll cover apply to any Unix flavor. What you see onscreen (particularly system prompts and responses) may differ slightly from what's illustrated in this book. The general ideas and specific commands, however, will be the same on all Unix systems.