Linux Directory Structure

Linux Directory	Function
/	The top directory of linux.
/bin	Store binary files which related to the system such as mount,ls,rm,etc.
/boot	Store files related to boot process.
/dev	Store information about all devices which connected to your linux.
/etc	Store configuration files about linux and its application.
/home	User directory.
/lib	Store library files.
/lost+found	lost+found is the directory in which fsck(filesystem check) will put files it restores from orphaned blocks.
/media	Usually used as a moint point for external media such as CD/DVD ROM.
/mnt	Used as a mount point directory,but it more likely a place that "temporarily mounted" device such as network shares.
/opt	Store files whcih not handled by package manager.
/proc	A virtual filesystem which used to provide information about the system.
/root	As root home directory.
/sbin	Store a binary files which usually can be run by superuser only.
/selinux	Store information about Security Enhanced.Some linux distribution may not have this directory.
/srv	Store data services which used by system.
/sys	Store information related about your linux system.
/tmp	Used as a temporary folder for applications.
/usr	Store user utilities and applications.
/var	Store variable data files.