What is Linux?

The ADL Linux stack — sketchbook view

Linux is a free, open-source operating system that powers everything from web servers to smartphones. If you are using an Android phone right now, you are already running Linux — Android is built on top of the Linux kernel.

Understanding Linux is the first step to understanding how ADL works. This page explains what Linux is, why it matters, and why it makes running a desktop on your phone possible.

What is an Operating System?

An operating system (OS) is the software that manages your device's hardware and provides a platform for applications to run. Think of it as the foundation of your device:

What you see	What the OS does behind the scenes
You tap an app icon	The OS launches the program and allocates memory
You type on the keyboard	The OS sends your keystrokes to the right application
You save a file	The OS writes data to storage and manages the file system
You connect to Wi-Fi	The OS communicates with the wireless hardware

Every computing device needs an operating system. The most common ones are:

Operating System	Used On	Made By
Windows	PCs and laptops	Microsoft
macOS	MacBooks and iMacs	Apple
Android	Phones and tablets	Google
iOS	iPhones and iPads	Apple
Linux	Servers, PCs, embedded devices	Community (open source)

The parts of a Linux system

Kernel vs. Distribution

Linux is actually two things, and understanding the difference is important.

The Linux Kernel

The kernel is the core of the operating system. It talks directly to your hardware — the processor, memory, storage, screen, and network. The kernel is what Linus Torvalds created in 1991, and it is what all Linux systems share.

Think of the kernel like the engine of a car. You never interact with it directly, but nothing works without it.

Linux Distributions

A distribution (or "distro") takes the Linux kernel and adds everything else you need: a desktop interface, a web browser, a file manager, a text editor, system tools, and more. A distribution is a complete, ready-to-use operating system.

Think of distributions like car models. They all have engines (the kernel), but they look different, have different features, and target different users:

Distribution	Best For	Character
Ubuntu	Beginners, general use	User-friendly, well-documented
Debian	Stability, servers	Rock-solid, conservative updates
Fedora	Developers, newest features	Cutting-edge, well-tested
Arch Linux	Advanced users	DIY, total control
Linux Mint	Windows switchers	Familiar, comfortable

ADL's guides use Ubuntu as the default distribution. We cover why in the What is Ubuntu? page.

Android IS Linux

Here is the key insight that makes ADL possible: Android is built on the Linux kernel. Your Android phone is already running Linux right now.

When you install ADL, you are not replacing Android. You are adding a Linux desktop alongside Android, sharing the same kernel. This is why:

• It does not void your warranty — you are not modifying the phone's system
• It does not require root — you work within Android's existing permissions
• It runs natively — programs run on the real Linux kernel, not through emulation
• Performance is good — there is no heavy translation layer slowing things down

What is Open Source?

Linux is open source, which means:

1. The source code is public — anyone can read, study, and understand exactly how it works
2. Anyone can contribute — thousands of developers worldwide improve Linux
3. It is free to use — you never pay for Linux itself
4. It is free to modify — you can customize it however you want
5. No single company controls it — it is maintained by a global community

This matters for ADL because every piece of software in the stack — from Termux to Ubuntu to XFCE — is open source. You are not locked into any company's ecosystem.

✅💡 Tip

Open source does not mean "no support." Ubuntu has a company behind it (Canonical) that provides professional support, and the Linux community has extensive documentation, forums, and help channels.

Comparing Linux to Other Operating Systems

Feature	Windows	macOS	Linux	Android
Cost	$100-200	Free (with hardware)	Free	Free (with hardware)
Source Code	Closed	Closed	Open	Partially open
Customization	Limited	Limited	Unlimited	Moderate
Hardware Support	Broad (PCs)	Apple only	Very broad	Mobile devices
Software Library	Huge	Large	Large	App stores
Desktop Environments	One (Windows Shell)	One (Aqua)	Many choices	One (launcher)
Package Manager	None built-in	None built-in	Yes (APT, etc.)	Play Store
Terminal Access	PowerShell, CMD	Terminal.app	Full access	Limited
User Control	Moderate	Moderate	Complete	Limited

Why Linux Matters for ADL

Linux is what makes the entire ADL project possible:

1. Shared kernel — Android and Linux desktop apps can coexist because they speak the same language
2. Mature software ecosystem — decades of desktop software are available
3. Lightweight options — Linux desktop environments can run well on mobile hardware
4. Open source — every component can be adapted for the Android environment
5. Active community — problems get solved and software keeps improving

Advantages of Linux

• Free — no license costs, ever
• Secure — strong permission model, fewer malware targets
• Customizable — change anything about your system
• Lightweight — can run well on limited hardware (perfect for phones)
• Stable — Linux servers run for years without rebooting
• Private — no built-in telemetry or forced accounts
• Well-documented — extensive community documentation

Disadvantages of Linux

• Learning curve — some tasks require terminal commands
• Software compatibility — some Windows/Mac apps are not available (though alternatives exist)
• Hardware support — some specialized hardware lacks Linux drivers
• Fragmentation — many distributions and desktop environments can be confusing for newcomers

ℹ️Note

Most of these disadvantages are less relevant for ADL. Since you are running Linux alongside Android, you still have access to all your Android apps. Linux fills in the gaps where Android falls short — productivity, development, and desktop workflows.

❓Frequently Asked Questions

Is Linux free?

Yes, completely free. Linux itself is open source and costs nothing. The applications you install on Linux are also overwhelmingly free. There are no license fees, no subscriptions, and no activation keys. Some companies sell support contracts for Linux, but the software itself is always free.

Is Linux hard to use?

Modern Linux with a desktop environment like XFCE is similar to using Windows or macOS. You have a taskbar, windows, a file manager, and a web browser. You can do most things by clicking, just like on any other operating system. The terminal is available for advanced tasks, but you do not need it for everyday use. ADL's setup process handles the complex parts for you.

Will Linux damage my phone?

No. ADL runs Linux inside a container on top of Android. It does not modify your phone's system, does not require root access, and does not touch your bootloader or firmware. You can uninstall it completely at any time, and your phone will be exactly as it was before. It is as safe as installing any other app from F-Droid.

Do I need to know programming to use Linux?

Not at all. While Linux is popular with programmers, it is a general-purpose operating system. You can browse the web, write documents, manage files, and watch videos without writing a single line of code. The ADL guides walk you through the technical details.

Summary

Linux is a free, open-source operating system kernel that powers everything from the world's largest servers to the phone in your pocket. Because Android already uses the Linux kernel, we can run a full Linux desktop on your phone without emulation or modification. This shared foundation is what makes ADL possible.

Next: Learn about Termux, the app that lets you access Linux tools on Android.