Welcome to Linux: The OS That Runs the World

Meet the operating system that powers phones, servers, supercomputers, and even Mars rovers

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What is Linux?

In 1991, a 21-year-old Finnish student named Linus Torvalds posted a message to a newsgroup: "I'm doing a (free) operating system (just a hobby, won't be big and professional)." He was wrong — it became the most widely used operating system in history.

1991
Linus Torvalds releases Linux 0.01 — just 10,000 lines of code
1992
Linux goes open source — anyone can view, modify, and share the code
2003
Android is built on the Linux kernel — eventually reaching billions of phones
2012
NASA's Curiosity rover lands on Mars — running Linux
Today
96.3% of the top 1 million web servers and all 500 top supercomputers run Linux

Free & Open Source

Anyone can download, use, modify, and share Linux. No license fee, ever.

Runs Everywhere

Phones, servers, rockets, fridges, cars, robots — if it computes, Linux probably runs it.

Community Built

Over 25,000 developers from around the world have contributed to the Linux kernel.

Fun Fact
Linux powers Android (which runs on 3+ billion devices), the International Space Station, the New York Stock Exchange, and every single one of the world's top 500 supercomputers.
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Linux is Everywhere

Can you guess which of these devices run Linux? Click each one to find out!

Android Phone
Web Server
Smart TV
Tesla Car
Supercomputer
Space Station
WiFi Router
Chromebook
iPhone
Windows PC
Click devices to guess which ones run Linux!
Fun Fact
Even Microsoft, which once called Linux "a cancer," now runs Linux on its Azure cloud servers and ships a full Linux kernel inside Windows (WSL)!
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The Kernel: Linux's Engine

A computer has layers, like a car. Click each layer to see what it does and how the pieces fit together.

Applications
Firefox, VS Code, Games, Terminal...
These are the programs you actually use. A web browser, a text editor, a game — they all sit at the top. They don't talk to the hardware directly; they ask the layers below for help.
Shell
Bash, Zsh — your command interpreter
The shell is your translator. When you type ls or cd, the shell converts your human-readable commands into instructions the kernel understands. It's how you "talk to" the operating system.
Kernel
The core of Linux — manages everything
This is Linux itself — the "brain" of the OS. The kernel manages memory, schedules tasks across CPU cores, handles file storage, and controls hardware devices. When an app needs to read a file, the kernel is the one that actually does it.
Hardware
CPU, RAM, Disk, Network, GPU...
The physical components of your computer. The CPU processes instructions, RAM holds temporary data, the disk stores files permanently, and the network card connects you to the internet. Hardware can't do anything without software telling it what to do.
Apps =
Passengers
Shell =
Steering Wheel
Kernel =
Engine
Hardware =
Wheels & Frame

Why "Kernel"?

Like the kernel of a nut — it's the core, the essential inner part that everything else wraps around.

Technically...

"Linux" is just the kernel. The full OS with apps and tools is called GNU/Linux — but everyone just says "Linux."

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The Filesystem: Everything Has a Place

Linux organizes files in a tree starting from a single root: /. Click directories to explore what they contain.

/ (root — the very top)
├── home
├── etc
├── var
├── tmp
├── usr
└── bin
Click any directory above to learn what it's for.

No Drive Letters!

Windows uses C:\, D:\, etc. Linux has a single tree starting at / — everything branches from there.

"Everything is a File"

In Linux, even hardware devices (like your mouse or USB drive) appear as files in the filesystem.

Case Sensitive

Documents and documents are completely different folders in Linux!

Fun Fact
The /tmp directory is automatically cleaned on reboot — it's the computer's scratch paper!
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The Shell: Your Command Center

The shell is a text interface to your computer. You type a command, the shell interprets it, asks the kernel to execute it, and shows you the result.

user@linux $ whoami
student
user@linux $ date
Sat Feb 7 10:30:00 UTC 2026
user@linux $ uname -a
Linux mytek 6.8.0 #1 SMP x86_64 GNU/Linux
user@linux $ _

Bash

The most common shell. "Bourne Again Shell" — the default on most Linux systems.

Zsh

A modern shell with better autocomplete and themes. Default on macOS.

The Prompt

The $ symbol means the shell is ready for your command. Type and press Enter!

Try It Yourself!

Click any command to see what it does:

whoami hostname date uptime uname -a
Linux Terminal
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Open Source: Built by Everyone

Linux isn't made by one company — it's built by a global community. Open source means anyone can see the code, improve it, and share it.

0
Linux kernel contributors (and counting)

See the Code

Every line of Linux source code is publicly available for anyone to read and study.

Change the Code

Found a bug? Add a feature? Anyone can modify the code and submit improvements.

Share the Code

You can freely distribute Linux and create your own version — that's how distros are born!

Linux Distributions — Click to learn more

Ubuntu
Most popular for beginners
User-friendly, huge community, great for desktops. Based on Debian. Used by millions worldwide.
Fedora
Cutting-edge features
Sponsored by Red Hat. Always has the latest software. Popular with developers who want new features fast.
Debian
Rock-solid stability
The "universal operating system." Prioritizes stability over newness. Many other distros (including Ubuntu) are based on it.
Arch Linux
For power users
Build your system from scratch. Rolling releases, minimal by default. Famous motto: "Keep It Simple."
Android
Linux for your pocket
Built on the Linux kernel by Google. Runs on 3+ billion phones and tablets. The most-used Linux-based OS by far!
Fun Fact
Linus Torvalds chose a penguin (Tux) as the Linux mascot because he was once bitten by a penguin at a zoo in Australia. He said it gave him "penguinitis!"
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Why Learn Linux?

Linux skills open doors in almost every area of technology. Here's where Linux knowledge takes you:

Software Dev
Build and deploy apps on Linux servers
Cybersecurity
Most security tools run on Linux
Cloud / DevOps
AWS, Google Cloud, Azure all run Linux
Data Science
Python, R, ML tools thrive on Linux
Robotics
ROS (Robot OS) is built on Linux
IoT / Embedded
Smart devices run lightweight Linux
Where will YOU use Linux? Pick your interests:
Gaming
Websites
Hacking / Security
AI / Machine Learning
Robots
Music / Audio
Space
Mobile Apps

Ready to start using Linux?

Linux Explorer!

You've discovered the operating system that powers most of the world's technology. From your phone to Mars rovers, Linux is everywhere — and now you know how it works!

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Devices Found
0
Layers Explored
0
Dirs Explored
0
Time Exploring

Linux Is Everywhere

Android phones, web servers, supercomputers, and space stations all run Linux.

Kernel + Shell + Apps

The kernel manages hardware, the shell takes your commands, and apps do the work.

Everything Is a File

Linux organizes everything in a tree structure starting from / (root).

Open Source Power

Anyone can see, modify, and share Linux — 25,000+ contributors built the kernel.

Ready to Create?

Put your new knowledge into practice!

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