Linux Directory Structure

Here's a good article that explains the file system structure in Linux:

Linux Directory Structure (File System Structure) Explained with Examples

Not every Linux distribution will have exactly the same directory structure as shown in this article.  For example, here are the directories under / in my PCLinuxOS installation:

/bin
/boot
/dev
/etc
/home
/initrd
/lib
/lost+found
/media
/mnt
/opt
/proc
/root
/sbin
/swap
/sys
/tmp
/usr
/var