| pathname | content |
| /bin | Commands required for minimal system operability |
| /boot | The kernel and the files needed to load the kernel |
| /dev | Equipment items for terminals, disks, modems, etc. |
| /etc | Critical startup files and configuration files |
| /home | user's home directory |
| /lib | Libraries for C compilers and parts of C compilers |
| /media | Mount point for file system on removable media |
| /opt | Optional application package |
| /proc | image of all running processes |
| /root | superuser's home directory |
| /sbin | Commands to boot, repair, or restore the system |
| /tmp | Temporary files that disappear on every reboot |
| /usr | Hierarchy of secondary files and commands |
| /usr/bin | Most commands and executables |
| /usr/include | Compile the header files of a C program |
| /usr/lib | Libraries, support files for use by standard programs |
| /usr/local | Local software (software written or installed by the user) |
| /usr/local/bin | local executable |
| /usr/local/etc | Local system configuration files and commands |
| /usr/local/lib | local support files |
| usr/local/sbin | Statically linked local system maintenance commands |
| /usr/local/src | Source code for /usr/local/* |
| /usr/man | Online User Manual |
| /usr/sbin | Less critical system administration commands and repair commands |
| /usr/share | Common to multiple systems (read only) |
| /usr/share/man | Online User Manual |
| /usr/src | Source code for non-native packages |
| /where | System-specific data and configuration files |
| / var / adm | All sorts of different things: logs, system settings records, weird admin messages |
| / var / log | Various system log files |
| / var / spool | Spool directory for printers, mail, etc. |
| /var/tmp | More temporary space (files are preserved after reboot) |
Note: This table is taken from Chapter 5 of "Linux System Administration Technical Manual".