Linux file system hierarchy

What is the main directory you need to know about to start using the Linux operation system,

here you can find a table you can use as a reference for the basic directory names and description.

Directory	Role
/	Root Directory, the head of the files tree
/home/	Contains the home directories of users, each user can put his files under his home directory.
/root/	The home directory for the super user (admin)
/usr/	Files (programs, lib, documentation, etc,) used by all users in the system.
/usr/bin/	Binaries (executable files) used by all users, included with the OS distribution
/usr/sbin/	Binaries (executable files) system files that comes with the distribution.
/usr/local/	Files that don’t come with the distributor and installed by the user
/usr/share/	Shared data by programs in /usr/bin/
/boot/	Has Boot loader, linux kernel, start up files.
/boot/initrd	start up files used by booting
/bin/	Common executable files that shared by the system administrator and users.
/sbin/	System binaries, used by the system and system admin
/lib/	shared libraries
/opt/	Optional software, Extras and third party software
/dev/	Devices node, (not a regular file), each device in the system is represented by file, so to write to the device, we write to this file, and to read from the file you read from this file.
/etc/	System configuration files,
/etc/fstab	Contains the a list of storage devices and their associated mount point
/etc/passwd	Contains a list of user accounts.
/var/	Storage for variable and temporary file created by user
/var/log	Log files
/var/log/messages	System log files
/net/	Standard mount point for entire remote file systems
/media/	Standard mount point for removable media devices e.g: CD-ROM, Digital Cameras, and USBs
/mnt/	Standard mount point for external file systems.
/proc/	Does not contain stored files, used to read information about system resources.
/sys/	same like /proc/
/tmp/	temporary space for by the system, cleaned upon reboot, so don’t use it to store any work!
/lost+found/	For every disk partition, contains files that were saved during failure are here.