Linux File Hierarchy Structure

The Linux file hierarchy follows a standard directory structure known as the Filesystem Hierarchy Standard (FHS). Here’s an overview of the key directories and what they typically contain:

1. / (Root Directory)
   • The top-level directory in the file system. All other directories and files are contained under this root directory.
2. /bin (Binaries)
   • Contains essential command binaries (programs) needed for system booting and repairing. These are available for all users.
3. /boot
   • Contains boot loader files, including the kernel, initrd (initial RAM disk), and other files needed to boot the system.
4. /dev (Devices)
   • Contains device files that represent hardware devices (like /dev/sda for storage, /dev/tty for terminals).
5. /etc (Configuration Files)
   • Contains system-wide configuration files for the operating system and installed applications (e.g., /etc/passwd, /etc/network/).
6. /home
   • User-specific directories. Each user typically has a subdirectory here (e.g., /home/username) where personal files and configurations are stored.
7. /lib (Libraries)
   • Contains shared libraries and kernel modules needed to boot the system and run programs in /bin and /sbin.
8. /media
   • Mount point for removable media (CDs, DVDs, USB drives, etc.). Devices are typically mounted here when inserted.
9. /mnt
   • A directory traditionally used for temporarily mounting file systems, like network shares or other disks.
10. /opt (Optional Packages)
    • Contains optional software packages and third-party applications that are installed manually (not through the system’s package manager).
11. /proc (Process Information)
    • Virtual filesystem that provides information about running processes, kernel parameters, and system statistics (e.g., /proc/cpuinfo for CPU info).
12. /root (Root User’s Home)
    • The home directory for the root (administrator) user.
13. /run
    • A temporary filesystem (usually mounted in RAM) that stores runtime data like currently running processes and other system states.
14. /sbin (System Binaries)
    • Contains essential system binaries used for system maintenance and troubleshooting, typically by the root user.
15. /srv (Service Data)
    • Contains data for services provided by the system, such as web server files or FTP server files (e.g., /srv/www for web content).
16. /sys (System Information)
    • Another virtual filesystem that exposes kernel and device information (like /sys/class for device classes).
17. /tmp (Temporary Files)
    • A directory for temporary files created by programs and users. Files here are usually deleted when the system reboots.
18. /usr (User Data)
    • Contains read-only user data, including applications and files that are shared among users. The directory is usually large and contains subdirectories like /usr/bin (user binaries), /usr/lib (libraries), and /usr/share (shared data).
19. /var (Variable Data)
    • Contains variable data files like logs, spool files, mail queues, and databases. It’s where dynamic content like system logs (/var/log) and mail files (/var/mail) are stored.

This structure is designed to keep things organized and make it easier to manage, especially for system administrators. Would you like more details about any specific directory?