The file system hierarchy

In Linux, all files are stored inside directories and directories are structured in a tree system which is call File System Hierarchy. 

The main directory is root. which is reffered as / mark. and the branches are directories and sub directories.

under root there are certain directories named bin, boot, dev, etc, home, root, run, sbin, tmp, usr and var.

Directories and contents

/etc          configuration files
/tmp        temporary files kept for 30 days
/root        home directory for administrator
/home     regular personal, user data and configuration files
/dev        h/w configuration files
/boot       files needed in boot process
/run         runtime data for processes started after the boot
/var         variable data which are unchanged between boots (cache,logs)
/usr         installed s/w, shared libraries

Summary

All directories are stored in a tree format. Root is at the top of all. There are fixed special directories, which are used to store certain types of files.
tags : file system hierarchy, /boot, /bin, /dev, /etc /root, /usr, /var,  linux, ubuntu, fedora, redhat, rhcsa, system admin, engineer, programing, cd, india