1) / (slash) :-
* / is called as root /super user .
* It is parent directory for all other directories.
* It is called as ROOT directory.
* It is represented by forward slash(/).
2) /root :-
* /root is home directory for root user(super user)
* It provides working environment for root user
3) /boot :-
* /boot contains bootable files Like Grub.conf .
4) /usr :-
* By default system software’s are installed in /usr directory.
5) /sbin :-
* /sbin contains commands used by only Super User(root)
6) /bin :-
* /bin contains commands used by all users and binary files.
7) /home :-
* It is home directory for all local users.
* It provides working environment for other users (other than root).
8) /etc :-
* /etc contains all configuration files like
> /etc/passwd for all local users details
> /etc/sysconfig/network uses for network file .
9) /opt :-
* /opt is optional directory for /usr/local.
* It contains all third party softwares.
10) /var :-
* /var is containing variable data like mails, log files.
11) /mnt :-
* /mnt is default mount point for any partition.
* It is empty by default.
* It contains all of removable media like cdrom, pen drive
12) /proc :-
* /proc contains all the process files
* This folder contents are not permanent, they keep change.
* It's file contain useful information used by OS like,
> /proc/meminfo To check system memory details.
>/proc/cpuinfo To check system cpu details.
13) /dev :-
* /dev contains device files like
/dev/hda for harddisk
/dev/cdrom for cdrom
14) /lib :-
* /lib contains library files which are used by OS.
* library files in linux are shared object files .
15) /tmp :-
* /tmp contains all the temp files.