| /bin | Essential user command binaries (for use by all users) |
| /boot | Static files of the boot loader, only used at system startup |
| /dev | Device files, links to your hardware devices like /dev/sound, /dev/input/js0 (joystick) |
| /etc | Host-specific system configuration |
| /home | User home directories. This is where you save your personal files |
| /lib | Essential shared libraries and kernel modules |
| /mnt | Mount point for a temporarily mounted filesystem like /mnt/cdrom |
| /opt | Add-on application software packages |
| /usr | /usr is the second major section of the filesystem. /usr is shareable, read-only data. That means that /usr should be shareable between various FHS-compliant hosts and must not be written to. Any information that is host-specific or varies with time is stored elsewhere. |
| /var | /var contains variable data files. This includes spool directories and files, administrative and logging data, and transient and temporary files. |
| /proc | System information stored in memory mirrored as files. |