  the filesystem hierarchy standard (fhs) defines the directory structure and directory contents in unix and unix-like operating systems, maintained by the linux foundation. the current version is 2.3, announced on 29 january 2004.(announce) fhs 2.3 released, from: christopher yeoh - 2004-01-29, email archive: freestandards-fhs-discuss (read-only), free standards group, sourceforge.net ==directory structure==  in the fhs all files and directories appear under the root directory "/", even if they are stored on different physical or virtual devices. note however that some of these directories may or may not be present on a unix system depending on whether certain subsystems, such as the x window system, are installed. the majority of these directories exist in all unix operating systems and are generally used in much the same way; however, the descriptions here are those used specifically for the fhs, and are not considered authoritative for platforms other than linux. {| class="wikitable" summary="a description of the hierarchy specified in the fhs." |- !directory !description |- | :/ |primary hierarchy root and root directory of the entire file system hierarchy. |- | :/bin |essential command binaries that need to be available in single user mode; for all users, e.g., cat, ls, cp. |- | :/boot |boot loader files, e.g., kernels, initrd. |- | :/dev |essential devices, e.g., :/dev/null. |- | :/etc |host-specific system-wide configuration files there has been controversy over the meaning of the name itself. in early versions of the unix implementation document from bell labs, /etc is referred to as the etcetera directory, a
Computer_standards File_system_directories Linux System_administration Unix_file_system_technology