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., ls, cp.
/boot/
Boot loader files, e.g., kernels, initrd; often a separate partition.
/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, as this directory historically held everything that did not belong elsewhere (however, the FHS restricts /etc to static configuration files and may not contain binaries). Since the publication of early documentation, the directory name has been re-designated in various ways. Recent interpretations include Backronyms such as "Editable Text Configuration" or "Extended Tool Chest".
/etc/opt/
Configuration files for /opt/.
/etc/X11/
Configuration files for the X Window System, version 11.
/etc/sgml/
Configuration files for SGML.
/etc/xml/
Configuration files for XML.
/home/
Users' home directories, containing saved files, personal settings, etc.; often a separate partition.
/lib/
Libraries essential for the binaries in /bin/ and /sbin/.
/media/
Mount points for removable media such as CD-ROMs.
/mnt/
Temporarily mounted filesystems.
/opt/
Optional application software packages.
/proc/
Virtual filesystem documenting kernel and process status as text files, e.g., uptime, network. In Linux, corresponds to a Procfs mount.
/root/
Home directory for the root user.
/sbin/
Essential system binaries, e.g., init, ip, mount.
/srv/
Site-specific data which is served by the system.
/tmp/
Temporary files (see also /var/tmp). Often not preserved between system reboots.
/usr/
Secondary hierarchy for read-only user data; contains the majority of (multi-)user utilities and applications.
/usr/bin/
Non-essential command binaries (not needed in single user mode); for all users.
/usr/include/
Standard include files.
/usr/lib/
Libraries for the binaries in /usr/bin/ and /usr/sbin/.
/usr/sbin/
Non-essential system binaries, e.g., daemons for various network-services.
/usr/share/
Architecture-independent (shared) data.
/usr/src/
Source code, e.g., the kernel source code with its header files.
/usr/X11R6/
X Window System, Version 11, Release 6.
/usr/local/
Tertiary hierarchy for local data, specific to this host. Typically has further subdirectories, e.g., bin/, lib/, share/
/var/
Variable files—files whose content is expected to continually change during normal operation of the system—such as logs, spool files, and temporary e-mail files. Sometimes a separate partition.
/var/cache/
Application cache data. Such data is locally generated as a result of time-consuming I/O or calculation. The application must be able to regenerate or restore the data. The cached files can be deleted without data loss
/var/lib/
State information. Persistent data modified by programs as they run, e.g., databases, packaging system metadata, etc.
/var/lock/
Lock files. Files keeping track of resources currently in use.
/var/log/
Log files. Various logs.
/var/mail/
Users' mailboxes.
/var/run/
Information about the running system since last boot, e.g., currently logged-in users and running daemons.
/var/spool/
Spool for tasks waiting to be processed, e.g., print queues and unread mail.
/var/spool/mail/
Deprecated location for users' mailboxes.
/var/tmp/ Temporary files to be preserved between reboots.
