The Linux file system is hierarchical, meaning directories can contain other directories and files.
Each directory has a specific purpose, making it easier to organize and manage files.
Understanding the file structure is crucial for navigating and administering a Linux system effectively.

Linux employs a hierarchical file system, organized like an inverted tree, with the root directory (/) at the top. This structure ensures efficient organization and management of files and directories.

Root Directory (/) In Linux

The top-level directory in the Linux file system , All other directories and files reside within it.

Key Directories and Their Roles:

1. Root Directory (/)
   The starting point of the file system. It Contains all other directories and files.

2. /bin(/usr/bin)
   Contains Everyday user command-line utilities accessible to all users.
   Stores essential binary executables, accessible to all users.
   Example: ls, cp, mv, rm

3. /boot
   -contain files that is used by boot loader.
   -Stores the boot loader and kernel images required to start the Linux system.

4. /dev
   Contains device files representing hardware devices (e.g., hard drives, CD-ROMs, printers).
   Example: /dev/sda1, /dev/sdb1 (hard drives), /dev/cdrom (CD-ROM drive)

5. /etc
   Contains system configuration files.
   Example: /etc/passwd, /etc/shadow, /etc/fstab

6. /home
   Contains user home directories, each with its own files and settings
   Example: /home/user1, /home/user2

7. /lib(usr/lib)
   Stores shared libraries used by programs.
   contain c programming library files needed by commands and apps
   Example: /lib/libc.so.6

8. /media
   Mount point for removable media.
   Example: USB drives, external hard drives

9. /mnt
   Mount point for temporary file systems.

10. /opt
    Contains optional software packages(Not Part of OS Applications).

11. /root
    Home directory of the root user.It is not same as /.

12. /sbin(/usr/sbin)
    Stores system administration tools, accessible only to root.
    Example: fdisk, mkfs

13. /tmp
    Stores temporary files.

14. /usr
    Contains most user programs and data.
    /usr/bin: User-level binaries
    /usr/lib: User-level libraries
    /usr/local: Locally installed software
    /usr/share: Shared data files

15. /var
    Stores variable data, such as System logs, mail, and temporary files.
    Example: /var/log, /var/mail, /var/tmp

16. /proc
    Virtual file system providing information about the system’s running processes and kernel.

17. /sys
    Provides information about the system’s hardware and devices.

18./media
Mount point for removable media (USB drives, external hard drives).

19./run
Runtime files and directories, such as PID files and socket files.

Example Scenario:

Let’s say you want to install a new software package, my_app. Here’s how the file system might be affected:

1. Installation: The package installer might create directories and files in /opt/my_app.
2. Configuration Files: Configuration files for my_app might be placed in /etc/my_app.
3. Executable Files: Executable files for my_app might be placed in /usr/local/bin.
4. Library Files: Shared library files required by my_app might be placed in /usr/local/lib.
5. Log Files: Log files generated by my_app might be placed in /var/log/my_app.

By understanding this hierarchical structure, you can efficiently navigate your Linux system, manage files, and troubleshoot issues.

Happy Learning..