Linux Directory Structure

Linux File System is organized in directories, each directory serves a purpose, here you can find a short but precise description for the most usefull directories:

Check this post to get the path where you are located in Linux.

/	The root directory, all directories start from this directory.
/bin	Has programs essential for the system.
/boot	Has the Linux kernel, files needed for the boot sequence and boot configuration files.
/dev	Everything in Linux is a file, a device recognized by the system is represented by a file.
/etc	Has system wide configuration files, some of the most important are: crontab: scheduled tasks fstab: mount points * passwd: users
/home	Has directories for each user, a good practice is to keep this directory on a seperate partition.
/lib	Shared libraries for the programs.
/lost+found	It keeps filesystem recovered files, normally is empty.
/media	Mount points for removable media like usb.
/mnt	For things you mount manually or with fstab.
/opt	Usually is used to install optionall software.
/proc	Its a virtual file system which keeps files for running processes.
/root	The home directory for the root user.
/sbin	Programs that used from the root user.
/tmp	Used to keep temporary files used by the processes, its emptied after a reboot.
/usr	Contains programs/files used by regular users.
/usr/bin	Contains programs installed by the Linux installer.
/usr/lib	Shared libraries for programs in /usr/bin.
/usr/local	Programs that are not installed by the Linux installer, but are used for system wide usage.
/usr/sbin	Programs executed with sudo or root user, usually system administration things.
/usr/share	Files shared by programs in /usr/bin.
/usr/share/doc	Documentation files of programs in /usr/bin.
/var	Holds files that usually changes over time, like databases files.
/var/log	Logs of various programs.