Linux Pocket Guide

Directory path part 2: scope

The scope of a directory path describes, at a high level, the purpose of an entire directory hierarchy. Some common ones are:

/	System files supplied with Linux (pronounced “root”)
/usr	More system files supplied with Linux (pronounced “user”)
/usr/games	Games (surprise!)
/usr/kerberos	Files pertaining to the Kerberos authentication system
/usr/local	System files developed “locally,” either for your organization or your individual computer
/usr/X11R6	Files pertaining to the X window system

So for a category like lib (libraries), your Linux system might have directories /lib, /usr/lib, /usr/local/lib, /usr/games/lib, and /usr/X11R6/lib. You might have other scopes as suits the system administrator: /my-company/lib, /my-division/lib, and so on.

There isn’t a clear distinction between / and /usr in practice, but there is a sense that / is “lower-level” and closer to the operating system. So /bin contains fundamental programs like ls and cat, /usr/bin contains a wide variety of applications supplied with your Linux distribution, and /usr/local/bin contains programs your system administrator chose to install. These are not hard-and-fast rules but typical cases.