What are the various folders in Linux for?

Http://www.ruanyifeng.com/blog/2012/02/a_history_of_unix_directory_structure.html

Http://www.pathname.com/fhs/pub/fhs-2.3.html

Http://lists.busybox.net/pipermail/busybox/2010-December/074114.html

/home:user home directories (optional)

Purpose

/home is a fairly standard concept, but it is clearly a site-specific filesystem. [9] The setup would differ from host to host. Therefore, no program should rely on this location. [10]

/root:home directory for the root user (optional)

Purpose

The root account's home directory may be determined by developer or local preference, but the the recommended default Location. [17]

/opt:add-on Application software Packages

Purpose

/OPT is reserved for the installation of add-on application software packages.

A installed in/opt must locate its static files in a separate/opt/<package> or/opt/<provider> Directory tree, where <package> is a name that describes the software package and <provider> is the provider ' s Lanana registered name.

/etc:host-specific System Configuration

Purpose

THE/ETC hierarchy contains configuration files. A "configuration file" is a local file used to control the operation of a program; It must be static and cannot is an executable binary. [4]

What are the various folders in Linux for?