Linux Basics for Beginners: A Practical Introduction

Linux is the foundation of many systems across the internet—from web servers and firewalls to mobile devices and cybersecurity labs. Whether you're diving into ethical hacking, system administration, or software development, learning Linux is a powerful first step.

This tutorial will walk you through the core concepts, commands, and tools needed to get started with Linux. No prior experience required.

What is Linux?

Linux is a family of open-source Unix-like operating systems based on the Linux kernel. Unlike Windows or macOS, Linux gives users deep control over their system—making it the preferred choice for developers and cybersecurity professionals.

Popular Linux distributions (distros) include:

• Ubuntu – User-friendly and widely used
• Kali Linux – Designed for penetration testing
• Debian – Stable and minimal
• CentOS / RHEL – Enterprise-grade servers

Linux File System Structure

Linux uses a hierarchical file system. Here are a few important directories:

Basic Linux Commands

Below are essential commands and their typical outputs, with inline comments explaining each action.

Navigation & Files

pwd                  # Print current working directory
ls                   # List files and folders in the current directory
cd Documents         # Change directory to "Documents"
mkdir test_folder    # Create a new directory named test_folder
touch notes.txt      # Create an empty file named notes.txt

Sample Output:

$ pwd
/home/user

$ ls
Documents  Downloads  Pictures  file.txt

File Operations

cp notes.txt notes_backup.txt   # Copy notes.txt to notes_backup.txt
mv notes.txt updated_notes.txt  # Rename notes.txt to updated_notes.txt
rm notes_backup.txt             # Delete notes_backup.txt
ls                              # Show current directory contents

System Info & Help

whoami            # Show the current logged-in user
uname -a          # Display system info (kernel, architecture)
top               # Display real-time system processes
man ls            # Open the manual page for the 'ls' command

File Permissions (rwx)

ls -l file.txt                  # Show file permissions and ownership
chmod 755 script.sh             # Change permissions to rwxr-xr-x
chown root:root script.sh       # Change ownership to root user and group

Sample Output:

-rwxr-xr-x 1 root root 0 Jul 21 12:00 script.sh

Package Management

Debian/Ubuntu (APT):

sudo apt update                 # Update package lists
sudo apt upgrade                # Upgrade installed packages
sudo apt install nmap           # Install 'nmap' package

Red Hat/CentOS (DNF):

sudo dnf install httpd          # Install Apache HTTP server

Networking Basics

ping google.com                 # Test internet connectivity
ip a                            # Show all IP addresses and interfaces
netstat -tuln                   # List all listening ports and services
curl ifconfig.me                # Display your public IP address

Useful Tools to Learn

Practice Environments

• TryHackMe – Linux Fundamentals
  https://tryhackme.com/module/linux-fundamentals

• OverTheWire – Bandit Wargame
  https://overthewire.org/wargames/bandit/

• Install a Virtual Machine:
  Use VirtualBox and Ubuntu to set up your own Linux practice lab.

Conclusion

Mastering Linux isn’t just about memorizing commands—it’s about understanding how systems work under the hood. Whether you're launching a career in cybersecurity or exploring development, learning Linux will empower you to work smarter, faster, and with greater control.

References

• TryHackMe – Linux Fundamentals
• Linux Foundation
• OverTheWire – Bandit