A sketch of the filesystem hierarchy.

     /        root directory of the filesystem

     /bin/    user utilities fundamental to both single-user and multi-user
              environments

     /bsd     pure kernel executable (the operating system loaded into memory
              at boot time).

     /dev/    block and character device files

              MAKEDEV  script for creating device files; see makedev(8)
              fd/      file descriptor files; see fd(4)

     /emul/   base directory for alternate areas searched first when system
              call emulation is in effect; see compat_freebsd(8),
              compat_linux(8),  compat_sunos(8),  compat_svr4(8).

     /etc/    system configuration files and scripts

              localtime    local timezone information; see ctime(3)
              disklabels/  backup disklabels; see disklabel(8)
              kerberosIV/  configuration files for the kerberos version IV;
                           see kerberos(1)
              mtree/       mtree configuration files; see mtree(1)
              namedb/      named configuration files; see named(8)
              uucp/        UUCP configuration files;

     /mnt/    empty directory commonly used by system administrators as a tem-
              porary mount point

     /sbin/   system programs and administration utilities fundamental to both
              single-user and multi-user environments

     /stand/  programs used in a standalone environment

     /tmp/    temporary files, usually a mfs(8) memory-based filesystem (the
              contents of /tmp are usually NOT preserved across a system re-
              boot)

     /usr/    contains the majority of user utilities and applications

              bin/      common utilities, programming tools, and applications
              contrib/  large packages contributed to Berkeley by outside par-
                        ties
              games/    useful and semi-frivolous programs
              include/  standard C include files

                        X11/         C include files for X11 window system
                        arpa/        C include files for Internet service pro-
                                     tocols
                                     System)
                        pascal/      include files for pc 1
                        protocols/   C include files for Berkeley service pro-
                                     tocols
                        sys/         system C include files (kernel data
                                     structures)
                        ufs/         C include files for UFS

              lib/      archive libraries
              libdata/  misc. utility data files
              libexec/  system daemons & system utilities (executed by other
                        programs)
              local/    local executables, libraries, etc.
              obj/      architecture-specific target tree produced by building
                        the /usr/src tree
              old/      programs from past lives of BSD which may disappear in
                        future releases
              sbin/     system daemons & system utilities (executed by users)
              share/    architecture-independent data files

                        calendar/  a variety of pre-fab calendar files; see
                                   calendar(1)
                        dict/      word lists; see look(1)

                                   words       common words
                                   web2        words from Webster's 2nd Inter-
                                               national
                                   papers/     reference databases; see re-
                                               fer(1)
                                   special/    custom word lists; see spell(1)

                        doc/       misc documentation; src for most of the
                                   printed 4.3BSD manuals (available from the
                                   USENIX association)
                        games/     ascii text files used by various games
                        man/       manual pages
                        me/        macros for use with the me macro package
                        misc/      misc system-wide ascii text files
                                   termcap     terminal characteristics
                                               database; see termcap(5)
                        mk/        templates for make; see make(1)
                        ms/        macros for use with the ms macro package
                        skel/      example . (dot) files for new accounts
                        tabset/    tab description files for a variety of ter-
                                   minals; used in the termcap file; see term-
                                   cap(5)
                        tmac/      text processing macros; see nroff(1) and
                                   troff(1)
                        zoneinfo/  timezone configuration information; see tz-
                                   file(5)

              src/      BSD and/or local source files
                        sbin/        src for files in /sbin
                        share/       src for files in /usr/share
                        sys/         kernel src files
                        usr.bin/     src for files in /usr/bin
                        usr.sbin/    src for files in /usr/sbin

     /var/    multi-purpose log, temporary, transient, and spool files

              account/   system accounting files

                         acct        execution accounting file; see acct(5)

              at/        timed command scheduling files; see at(1)
              backups/   misc. backup files
              db/        misc. automatically generated system-specific
                         database files
              games/     misc. game status and log files
              log/       misc. system log files

                         wtmp        login/logout log; see wtmp(5)

              mail/      user mailbox files
              preserve/  temporary home of files preserved after an accidental
                         death of an editor; see ex(1)
              quotas/    filesystem quota information files
              run/       system information files describing various info
                         about system since it was booted

                         utmp        database of current users; see utmp(5)

              rwho/      rwho data files; see rwhod(8),  rwho(1),  and rup-
                         time(1)
              spool/     misc. printer and mail system spooling directories

                         ftp/        commonly ~ftp; the anonymous ftp root di-
                                     rectory
                         mqueue/     undelivered mail queue; see sendmail(8)
                         output/     line printer spooling directories
                         secretmail/
                                     secretmail spool directory; see xget(1)
                         uucp/       uucp spool directory
                         uucppublic/
                                     commonly ~uucp; public uucp temporary di-
                                     rectory

              tmp/       temporary files that are kept between system reboots

SEE ALSO

     ls(1),  apropos(1),  whatis(1),  whereis(1),  finger(1),  which(1),
     find(1),  grep(1),  fsck(8)

HISTORY