What are the standard Linux directories, like
/bin - common binaries
/sbin - Binaries used for system administration are placed here.
/boot - static files of the boot loader
/dev - device files such as your CD drive, hard disk, and any other physical device.
/home - user home directories are found here.
/lib - Essential shared libraries and kernel modules
/mnt - temporary mount point useful for when you insert your USB stick etc.
/var - variable data, such as logs, news, mail spool files and so on which is constantly being modified by various programs running on your system.
/tmp - temporary files are placed here by default.
/usr - the secondary hierarchy which contain its own bin and sbin sub-directories.
/etc - Usually contain the configuration files for all the programs that run on your system.
/opt - Third party application packages which does not conform to the standard Linux file hierarchy can be installed here.
/srv - Contains data for services provided by the system.
Debian definition: http://www.debian.org/doc/debian-policy/ch-opersys.html
This one seems "good enough" for me to link it, but I don't know what's the exact origin: http://www.pathname.com/fhs/pub/fhs-2.3.html
The google keyword is "file system hierarchy".
If you will look to the right --> There is a Related section that has a link to this question which provides the same information as the question you asked and answered.