The Linux directory structure is a tree-like hierarchy hierarchy of directories and files. At the base of the filesystem is the “/” directory, otherwise known as the “root” (not to be confused with the root user). Unlike DOS or Windows filesystems that have multiple “roots”, one for each disk drive, the Linux filesystem mounts all disks somewhere underneath the / filesystem. The following table describes many of the most common Linux directories.
/ - The nameless base of the filesystem. All other directories, files, drives, and devices are attached to this root. Commonly (but incorrectly) referred to as the “slash” or “/” directory. The “/” is just a directory separator, not a directory itself.
/bin - Essential command binaries (programs) are stored here (bash, ls, mount, tar, etc.)
/boot - Static files of the boot loader.
/dev - Device files. In Linux, hardware devices are acceessd just like other files, and they are kept under this directory.
/etc - Host-specific system configuration files.
/home - Location of users’ personal home directories (e.g. /home/susan).
/lib - Essential shared libraries and kernel modules.
/proc - Process information pseudo-filesystem. An interface to kernel data structures.
/root - The root (superuser) home directory.
/sbin - Essential system binaries (fdisk, fsck, init, etc).
/tmp - Temporary files. All users have permission to place temporary files here.
/usr - The base directory for most shareable, read-only data (programs, libraries, documentation, and much more).
/usr/bin - Most user programs are kept here (cc, find, du, etc.).
/usr/include - Header files for compiling C programs.
/usr/lib - Libraries for most binary programs.
/usr/local - “Locally” installed files. This directory only really matters in environments where files are stored on the network.Locally-installed files go in /usr/local/bin, /usr/local/lib, etc.). Also often used for software packages installed from source, or software not officially shipped with the distribution.
/usr/sbin - Non-vital system binaries (lpd, useradd, etc.)
/usr/share - Architecture-independent data (icons, backgrounds, documentation, terminfo, man pages, etc.).
/usr/src - Program source code. E.g. The Linux Kernel, source RPMs, etc.
/usr/X11R6 - The X Window System.
/var – Variable data: mail and printer spools, log files, lock files, etc.