Linux-Directory Layout

Directory Description
  The nameless base of the file system. 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 accessed 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/dhanoop).
/lib Essential shared libraries and kernel modules.
/proc Process information pseudo-file system. An interface to kernel data structures.
/root The root (super-user) 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.