What Is Linux?
Linux is an operating system, like the Windows and macOS you may already know, but it is open source. An operating system is the software that sits between your hardware, such as the processor, memory, and storage, and the applications you run, such as a browser or a music player.
Technically, the word Linux refers to the kernel, the core of the operating system. We'll get into that in a moment.
A Brief History of Linux
The Linux story begins in 1991, when Linus Torvalds, a Finnish student, started writing an operating system kernel as a hobby project. He shared the code openly and invited others to contribute. What began as a small one-person project slowly grew as more and more developers around the world fixed bugs and added features.
Earlier, in 1983, Richard Stallman had launched the GNU project with the goal of building a free operating system. GNU had plenty of supporting tools, such as a compiler and a shell, but no mature kernel. The Linux kernel filled that gap. That's why some people call the system GNU/Linux.
| Year | Event |
|---|---|
| 1983 | Richard Stallman starts the GNU project. |
| 1991 | Linus Torvalds releases the first Linux kernel. |
| 1993 | The first distributions appear, including Slackware and Debian. |
| 2008 | Android, built on the Linux kernel, debuts on its first commercial device. |
Tux, the Linux mascot. Illustration by Larry Ewing.
Kernel, Operating System, and Distribution: What's the Difference?
Think of a car. The kernel is the engine, the core part that produces power and moves everything. But an engine alone won't get you anywhere. You also need seats, a steering wheel, a dashboard, and wheels. Those are like the applications, shell, and graphical interface that turn the kernel into a complete operating system. The finished car, ready to drive, is what we call a distribution, or distro.
| Term | Description |
|---|---|
| Kernel | The core of the system, which manages the processor, memory, and hardware. |
| Operating system | A kernel bundled with basic tools and supporting applications. |
| Distribution (distro) | A ready-to-use operating system package, such as Ubuntu, Debian, or Fedora. |
Don't worry, we'll cover distributions in more depth in the next article.
What Does the Kernel Actually Do?
If the kernel is the engine, what is it doing all day? Every time you open an app, save a file, or connect to Wi-Fi, the kernel is working behind the scenes. Its main jobs include:
- Process management: Decides which program gets the processor, when, and for how long, so many applications can run at once.
- Memory management: Hands out memory to each program and makes sure one program can't trample another's memory.
- Device drivers: Talk to hardware like the keyboard, graphics card, and network card.
- File system: Controls how data is stored, read, and found on disk.
- Security and permissions: Decides who can read, modify, or run a given file.
Without a kernel, applications would have no way to "talk" to the hardware. That's why the kernel is called the heart of the operating system.
The Main Components of a Linux System
The Linux system you use day to day is actually built from several layers working together.
| Component | Role |
|---|---|
| Bootloader | The first program to run when the computer powers on; it loads the kernel into memory. |
| Kernel | Manages hardware resources and provides basic services to other programs. |
| Init system | The first process the kernel starts, which then launches other services in the background. |
| Shell | A text-based interface where you type commands and read the results. |
| Desktop environment | The full graphical experience with windows, icons, menus, and panels, such as GNOME or KDE Plasma. |
| Applications and package manager | The programs you use, plus the tools to install, update, and remove them. |
Linux's big strength is that it's modular. Any of these components can be swapped out without replacing the whole system. You can change your desktop to suit your taste and keep the same kernel. This freedom is what gave rise to so many distributions, each with its own personality.
Why Is Linux Free? Understanding Open Source
The Linux kernel is released under the GNU General Public License (GPL). That means the source code is open to everyone. Anyone is free to:
- Run the program for any purpose.
- Study how it works and change it to fit their needs.
- Share copies with others.
- Share their modified versions.
Note that "free" here doesn't only mean zero cost. It refers to the user's freedom. That's why plenty of companies still build businesses around Linux, for example through technical support and consulting.
The model has practical benefits too. Because the code is open, anyone can inspect it for security holes or bugs. A fix made by one person can immediately benefit millions of other users. This is one of the reasons Linux has grown so fast and earned trust in so many fields.
The Philosophy Behind Linux
Linux inherited its way of thinking from the older Unix operating system. A few ideas you'll run into again and again as you learn:
- Small, focused programs: Each program is designed to do one thing well, and programs are then combined to get bigger jobs done.
- Text-based configuration: System settings usually live in plain text files that anyone with permission can read and edit.
- The user stays in control: The system doesn't hide what's happening behind the scenes. You're free to look, change, and fix.
This mindset can feel foreign at first, especially if you're used to systems that do everything automatically. Once you get the hang of it, though, you'll appreciate how flexible and predictable Linux is.
Where Is Linux Used?
- Servers and the internet: Many of the servers running websites and online services use Linux.
- Cloud computing: Cloud platforms generally run Linux under the hood.
- Phones: Android is built on the Linux kernel.
- Supercomputers: In recent years, the TOP500 list has been dominated entirely by Linux-based systems.
- Embedded devices: Routers, smart TVs, even in-car entertainment systems.
- Desktops and laptops: Distributions like Ubuntu, Fedora, and Linux Mint.
As these examples show, Linux is already part of our everyday digital lives. Chances are you've been using Linux without realizing it.
Why Should You Learn Linux?
- Career opportunities: Roles like system administrator, DevOps engineer, cloud engineer, backend developer, and security engineer all lean heavily on Linux.
- Full control: You know what's running on your computer and you can manage all of it.
- Light and flexible: Linux can bring an old laptop back to life.
- A big community: Documentation and help forums are everywhere.
- A foundation for other tech: Docker, Kubernetes, and many cloud services are rooted in Linux.
Common Myths About Linux
Before you start learning, let's clear up a few common misconceptions.
"Linux is only for programmers." Not true. Modern distributions come with friendly graphical interfaces, complete with a browser, office apps, and a media player. Plenty of people use Linux every day without ever writing a line of code.
"Linux is hard." Linux does have a learning curve, especially if the terminal is new to you. But you don't have to master everything at once. Start with the simple stuff and build up bit by bit.
"Linux can't get viruses." Linux is designed around a strict permissions model, but no system is truly immune. You still need safe habits, like keeping the system updated and installing software only from trusted sources.
"Free means low quality." Quite the opposite. Much of the high-quality software holding up the modern internet came out of the open source community.
Tips for Starting Your Linux Journey
You don't have to wipe your current operating system to try Linux. Here are a few safe ways to get started:
- Use a virtual machine: Install Linux inside a program like VirtualBox so your main system stays untouched.
- Try live mode: Many distributions can run straight from a USB drive without being installed on your computer.
- Practice basic commands: Get comfortable with the terminal through simple commands, then level up gradually.
- Lean on the community: Don't hesitate to ask in forums or discussion groups. Almost every problem you run into has already hit someone else.
- Be consistent: A little learning every day beats a big cram session once in a while.
Summary
- Technically, Linux refers to the kernel, the core of an open source operating system.
- Linux started as Linus Torvalds's hobby project in 1991 and was completed with software from the GNU project.
- The kernel is the core of the system, managing processes, memory, hardware, and permissions; the operating system is the collection of software that forms a complete system; and a distribution is a ready-to-use operating system package.
- Linux systems are modular, so each component can be swapped to fit your needs.
- Linux runs on servers, cloud services, phones, supercomputers, and home devices.
- Learning Linux opens up many career opportunities and is a foundation for understanding modern technology.
- You can try Linux safely with a virtual machine or live mode.
Now you know what Linux is and why it matters so much. In the next article, we'll look at Linux distributions: why there are so many "flavors" of Linux, and how to pick the one that suits you best.
References
- GNU Project. (2026, June 9). What is Free Software? https://www.gnu.org/philosophy/free-sw.html
- Linux Kernel Documentation. (n.d.). License Rules. https://docs.kernel.org/process/license-rules.html
- W3Techs. (2026). Usage Statistics of Operating Systems for Websites. https://w3techs.com/technologies/overview/operating_system
- Android Open Source Project. (2026, October 9). Kernel Overview. https://source.android.com/docs/core/architecture/kernel
- TOP500. (2026). TOP500 List – June 2026. https://top500.org/lists/top500/2026/06/