Filesystem Hierarchy Standard (FHS)

I wanted to begin with the Filesystem Hierarchy Standard (FHS) which is currently at version 3.0. The standard can be referenced below as well as at http://refspecs.linuxfoundation.org/fhs.shtml.

Filesystem Hierarchy Standard 3.0

When I first began using Linux, I realized that all the files and directories were arranged in a particular way. I wondered why Linux always seemed to have this organization and what each directory was for. After many years of just “going with it” I finally came across this resource. It was originally written in 2004 but version 3.0 was released in 2015. Its goal is, “to support interoperability of applications, system administration tools, development tools, and scripts as well as greater uniformity of documentation for these systems.”

The hierarchy is as follows:

Directory Description
bin Essential command binaries
boot Static files of the boot loader
dev Device files
etc Host-specific system configuration
lib Essential shared libraries and kernel modules
media Mount point for removable media
mnt Mount point for mounting a filesystem temporarily
opt Add-on application software packages
run Data relevant to running processes
sbin Essential system binaries
srv Data for services provided by this system
tmp Temporary files
usr Secondary hierarchy
var Variable data