Linux Filesystem Hierarchy

Linux Filesystem or Directory Structure

Filesystem Hierarchy Standard (FHS) defines the directory structure and directory contents, the names, locations, and permissions for many file types and directories in Linux.

The Directory Structure of Linux is as Below.

Directory	Content
/	Primary hierarchy root and root directory of the entire file system hierarchy.
/bin	Common programs, commands binaries (executables) shared by the system, the system administrator and the users. It needs to available in single user mode. Ex cat, ls ,cp.
/boot	The startup files required to boot the system e.g. The kernel, vmlinuz. In some recent distributions also called GRUB.
/dev	Device files. These include terminal devices, usb, or any device attached to the system.
/etc	Most important system configuration files are in /etc, It should contain no binaries; any binaries should be moved to /bin/ or /sbin/
/home	Home directories of the common users.
/lib	Library files that needed to execute the binaries in /bin/ and /sbin/. These shared library images are used to boot the system or execute commands within the root file system.
/lost+found	Every partition has a lost+found in its upper directory. Files that were saved during failures are here.
/mnt	The /mnt/ directory is used for temporarily mounted file systems, such as NFS file system mounts.
/media	Mount point for removable media. Such as CD-ROM, USB storage etc.
/opt	Contains extra and third party software and add-on packages that are not systems default software. A software package that installs to /opt/ creates a directory bearing its name, e.g. /opt/packagename/.
/proc	It contains information about system resources that either extract information from the kernel or send information to it. Examples of such information include system memory, cpu information, and hardware configuration.
/root	The administrative user's home directory. Note the difference between /, the root directory and /root, the home directory of the root user.
/sbin	Contains binaries for use by the system and the system administrator. /sbin/ require root privileges to use
/srv	Site specific data that served by the system. This directory gives users the location of data files for a particular service, such as FTP, WWW, or CVS.
/tmp	Temporary space for use by the system, cleaned upon reboot, so don't use this for saving any work.
/usr	Programs, libraries, documentation etc. for all user-related programs. The /usr/ directory is often on its own partition and is mounted read-only.
/var	Storage for all variable files (continuously changing files) and temporary files created by users, such as log files, the mail queue, the print spooler area.

 Fig : Filesystem Hierarchy in Linux

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