Linux Top level Directory structure

Pranaam to all bhai ji _/\_

in this post we will discuss about linux top level directory structure that is basic directory structure of Linux.
linux main directory is 'slash' ( / ).
like in windows, we have 'c' drive which is starting graphical point where OS stores its data on hard disk , in linux we have  /  . rest of the directories comes under / directory or we can say / is the main directory from where rest of the directories start as a branch :)

here is the list of main directories under / directory in linux.
bin
boot
dev
etc
home
lib
media
mnt
opt
proc
root
sbin
selinux
tmp
usr
var

bin directory
This directory contains binary files of system or can say those executable which are needed by system. mainly,commands are stored in this directory  like cat , ls , cp , mv etc.
admin as well as normal user on that machine can use these commands or admin can restrict users to use these commands by changing permission on these commands for "other" user category.

boot directory
 This is the dirctory which contain files which are required by system during booting like karnal , image that help to mount / during booting when system drivers are not loaded, boot  configuration file(grub loader file).

dev directory
Directory which contain all the devices of system mounted here i.e our partition(/dev/sda*) our usb drive (/dev/sdb or something like that), our Buses , terminals on system (/dev/tty*)  CD/DVD drive.
this directory is all about devices available on our system.

etc directory
etc is the directory which play an important role in linux system handling  :). This directory is the one which contains files related to authentication(pam libraries , shadow and passwd file) , configuration files of various application installed on linux is stored by this directory .if we want to make changes in working of any installed package on system, we will need to find out config file of that package in /etc directory.

home directory
As  name represent , this directory contains home directories of user other then root user and services(apache,ssh,telnet etc).If we have a user having name ICA , home directory will be at location /home/ICA for user ICA. when user will login to system , user drops to his home directory and he can create/edit/delete files in his home directory.

lib directory
it is the place where linux store its shared library (shared by commands/various application installed on system/system itself ). library files are mainly with extension ".so". one library can be shared by more then one program .

media directory
when we plugin removable media , that will be mount in this directory . a sub directory creates in media directory and then system mount on that sub directory and if you are using graphical user interface, mounted device will display on desktop.

mnt directory
mnt is also mounting directory where we can mount devices and then can access them.

opt directory
this directory is mainly used for the those software/programs which are optional or coded by system user himself .opt directory contain those packages which are not part of default linux installation.

proc directory
if we term proc directory as RAM data holder , it wont be wrong :) . proc directory contains the information about processes running on system.when we open this directory , there exist folders with combination of random numbers , those are nothing but the folder related to process whose ID is the same as folder name .
and you will get the files and related to that process in that folder.

root directory
this is the home directory of system by default super user known as root.this is not accessible by any user other then root or the user who have root user privileges.people call / as root of linux but there is directory in linux under / whose name is root :).

sbin Director
like bin directory , sbin also contains executable binaries but these binaries are only for administrative task like for booting  and backup. other user cant use binaries present in sbin directory.

tmp directory
as name reflects , this directory is mainly used by user/system/package just to save files temporarily .
this directory has read/write/execute permission for every user(but protected with sticky bit which wont let delete other user's stuff in tmp folder) .user use it for temporary use for storing files.this is temporary directory so dont store anything in this directory if you want to store your stuff permanently .

usr directory
this directory contains resources which will be used by the user on that machine and these resources(binaries, application usage document and other libraries ) will be shared among them . this directory contain shared files for user, thats why this directory provide read only permission to user.

var directory
this directory contains such data which keeps changing as system runs like logs and system lock.size of those files which contains logs/message also keep changing.

Thank you 
Greetz to:- Guru ji zero and whole Team IndiShell <3