The Linux file system follows a hierarchical structure, often referred to as the Linux directory structure or Filesystem Hierarchy Standard (FHS). It organizes files and directories into a tree-like structure, starting from the root directory (/). Here's a breakdown of the typical Linux file structure with descriptions of common directories and options associated with them.

1. / (Root Directory)

• Description: The root directory is the top-level directory in the file system. All other directories are subdirectories of this root directory.
• Example:

  /
  ├── bin/
  ├── home/
  ├── etc/
  ├── var/
  ├── lib/
  └── usr/
  

2. /bin

• Description: Contains essential command binaries (executables) needed for the system to function in single-user mode. These are required for basic system functionality, such as ls, cp, cat, etc.
• Example:

  /bin/ls
  /bin/cp
  /bin/bash
  

3. /boot

• Description: Holds files required for booting the system, such as the Linux kernel and bootloader configuration files.
• Example:

  /boot/vmlinuz
  /boot/grub/
  

4. /dev

• Description: Contains device files that represent hardware devices (like hard drives, USB devices, and terminals). These files provide an interface for interacting with hardware.
• Example:

  /dev/sda
  /dev/tty0
  /dev/null
  

5. /etc

• Description: Contains system configuration files and scripts used by various system programs. This is where the main configuration files for system services reside.
• Example:

  /etc/passwd        # User account information
  /etc/fstab         # File system table
  /etc/hostname      # Hostname
  

6. /home

• Description: Contains the personal directories of all users on the system. For example, /home/john would be the home directory for the user john.
• Example:

  /home/john/
  /home/jane/
  

7. /lib

• Description: Contains essential shared libraries required by system binaries in /bin and /sbin. These libraries are necessary for system programs to function.
• Example:

  /lib/x86_64-linux-gnu/
  /lib/libc.so.6
  

8. /media

• Description: This directory is used to mount removable media like CDs, DVDs, and USB drives. It provides a location where removable media can be accessed.
• Example:

  /media/usb/
  /media/cdrom/
  

9. /mnt

• Description: A temporary mount point for mounting filesystems, usually used for mounting storage devices during system maintenance or administration.
• Example:

  /mnt/external_drive/
  

10. /opt

• Description: Contains optional software packages that are not part of the default system installation. These are often third-party applications installed manually.
• Example:

  /opt/google/
  /opt/lampp/
  

11. /proc

• Description: A virtual file system that provides information about system processes and kernel parameters. The files in this directory do not exist on disk but are created dynamically by the kernel.
• Example:

  /proc/cpuinfo
  /proc/meminfo
  /proc/1/status
  

12. /root

• Description: The home directory for the system's root user (superuser). This is different from /home, which contains regular users' home directories.
• Example:

  /root/.bashrc
  

13. /run

• Description: Contains runtime data for processes started since the last boot, including system information and PID files for services.
• Example:

  /run/utmp         # User login information
  /run/lock         # Lock files for running processes
  

14. /sbin

• Description: Contains system binaries (executables) used for system administration tasks, such as fsck, mount, and shutdown. These programs are typically for the root user.
• Example:

  /sbin/mount
  /sbin/reboot
  

15. /srv

• Description: Contains data for services provided by the system, such as web or FTP servers.
• Example:

  /srv/http/        # Web server data
  /srv/ftp/         # FTP server data
  

16. /sys

• Description: A virtual file system providing information about devices, kernel parameters, and more. It is used for kernel and device management.
• Example:

  /sys/class/
  /sys/block/
  /sys/devices/
  

17. /tmp

• Description: A directory for temporary files used by applications or the system. Files in /tmp are often cleared upon reboot or after a certain period.
• Example:

  /tmp/tempfile.txt
  

18. /usr

• Description: Contains system-wide read-only data and programs. It holds most user utilities and applications, as well as libraries and documentation.
  • /usr/bin/: Essential user command binaries
  • /usr/lib/: Shared libraries
  • /usr/share/: Architecture-independent data, such as documentation
• Example:

  /usr/bin/ls
  /usr/lib/libc.so
  

19. /var

• Description: Contains variable files, such as logs, caches, and databases. It is meant for files that are expected to grow or change during normal system operation.
  • /var/log/: Log files
  • /var/lib/: State information for applications
  • /var/spool/: Mail, print queues, etc.
• Example:

  /var/log/syslog
  /var/spool/mail
  

Summary of Common Directories

This file structure ensures consistency and organization, allowing for easier system maintenance and management.