Linux, Unix, macOS and Windows are all operating systems: the core software that runs a computer, manages its hardware, and lets you open apps.
They differ in who makes them, what they cost, whether their code is open, and where they are used. This guide explains the difference between Linux, Unix, Mac and Windows in plain language.
Windows is Microsoft’s paid, closed-source system and the most common choice for home and office PCs. macOS is Apple’s system for Mac computers, built on Unix foundations. Linux is a free, open-source, Unix-like system that runs most servers and Android phones. Unix is the older family that inspired macOS and Linux and still runs some business servers.
The Four Systems at a Glance
| System | Made by | Cost | Source code | Runs on | Best known for |
|---|---|---|---|---|---|
| Windows | Microsoft | Paid licence, usually included with a new PC | Closed | PCs from many brands | Home, office, and gaming PCs |
| macOS | Apple | Included with every Mac | Mostly closed, open-source Darwin core | Apple Mac computers only | Creative work and Apple users |
| Linux | A global community, with many distributions | Mostly free | Open source | Almost any hardware, from laptops to servers | Servers, cloud, developers, Android |
| Unix | Started at Bell Labs; now commercial vendors | Commercial licences | Mostly closed | Specialist business servers | Long-running enterprise systems |
What Each Operating System Is
Windows
Windows is made by Microsoft and is the most widely used desktop operating system. Most PCs from brands such as Dell, HP, and Lenovo come with it.
It has the largest library of desktop software and games. It is closed source, so only Microsoft can change its code.
macOS
macOS is Apple’s operating system, and it runs only on Mac computers. It is built on Darwin, an open-source core with roots in BSD Unix.
Recent versions are certified as UNIX 03 by The Open Group, so macOS is a true Unix system with Apple’s interface on top.
Linux
Linux began in 1991, when Linus Torvalds released a free kernel, the core part of an operating system. It is Unix-like: it behaves like Unix but was written from scratch.
Linux comes in many free versions called distributions, such as Ubuntu, Linux Mint, and Fedora. It also powers Android phones, most web servers, and nearly all of the world’s fastest supercomputers.
Unix
Unix was created at AT&T’s Bell Labs, starting in 1969. Many ideas in modern computing, such as small tools that work together and a single folder tree, come from it.
Today, traditional Unix mainly runs specialist business servers, using commercial systems such as IBM AIX and Oracle Solaris.
How Unix, macOS, Linux and Windows Are Related
Think of Unix as the ancestor. macOS descends from it through BSD, and Linux was designed to behave like it.
Windows comes from a different line. Modern Windows is based on Windows NT, which Microsoft built separately, so it works differently from the Unix family.
That shared Unix heritage is why macOS and Linux feel alike in places, such as their Terminal commands and folder structure.
Deciding between a Mac and a Windows PC? This comparison covers price, software, and everyday use.
Key Differences Explained
Cost
Most Linux distributions are free to download and use. Windows needs a paid licence, though the cost is usually included in a new PC.
macOS updates are free, but macOS only runs on Macs, so the real cost is Apple hardware. Commercial Unix is licensed to businesses.
Open Source vs Closed Source
Linux is open source: anyone can read, change, and share its code. Windows is closed source. macOS is mostly closed, although its Darwin core is open source.
Hardware Support
Windows runs on PCs from many manufacturers. macOS runs only on Apple’s own Macs.
Linux runs on the widest range of devices, from old laptops to servers and small boards such as the Raspberry Pi.
Software and Gaming
Windows has the largest choice of desktop apps and games. macOS is strong for creative software such as Final Cut Pro and Logic Pro.
Linux has many free apps, and gaming has improved through Valve’s Proton compatibility layer. Some popular programs and games with anti-cheat software still do not run on it.
Security and Updates
All four can be secure when kept updated. Windows is targeted by more malware, mainly because it is the most widely used.
Windows and macOS update through built-in tools. Linux distributions use a package manager that updates the system and most apps together.
The Command Line
macOS and Linux share a Unix-style terminal, so many commands work on both. Windows uses Command Prompt and PowerShell, which use different commands.
Windows can also run Linux tools through the Windows Subsystem for Linux (WSL).
To try Linux without changing your PC, boot it from a USB stick in “live” mode or run it in a virtual machine. Nothing is installed on your drive unless you choose to.
Which One Should You Choose?
- Windows: the widest choice of software and games, and hardware at every price.
- macOS: a polished system that works closely with iPhone and iPad, and is strong for creative work.
- Linux: free, customisable, and popular with developers. It can also give an older PC a second life.
- Unix: not a home choice. It is used by organisations running specialist servers.
For programming, all three desktop systems work well. Linux and macOS share the Unix tools many servers use, and Windows covers them through WSL. If you use both desktop platforms, follow the practical guide to share files between Mac and Windows.
Can You Use More Than One?
Yes. You can dual-boot Windows and Linux on one PC and choose which to start each time.
You can also run one system inside another with a virtual machine. On Windows, WSL runs Linux tools without a separate install.
How to run Linux or another operating system safely inside the one you already use.
Frequently Asked Questions
What is the main difference between Linux, Unix, Mac and Windows?
They differ in openness, cost, and purpose. Windows is paid and closed, macOS is Apple’s Unix-based system, Linux is free and open-source, and Unix is the older commercial family they descend from.
Is macOS based on Unix?
Yes. macOS is built on a Unix foundation and is officially Unix-certified. This gives it a stable, secure base, which is one reason it differs from Windows.
Is Linux the same as Unix?
No. Linux is Unix-like, meaning it works in a similar way, but it was written separately with free, open code. True Unix systems are commercial and used mainly on business servers.
Which is more secure, Windows, Mac, or Linux?
All can be secure when kept updated. Windows faces the most malware because it is the most common, while macOS and Linux face fewer threats, partly due to smaller share and strong design.
Is Linux free while Windows and Mac are paid?
Linux is free to download and use. Windows is paid, usually bundled with a PC. macOS is free but runs only on Apple hardware, which you pay for.
Which operating system should a beginner choose?
Most beginners are best served by Windows or macOS, which are polished and easy to learn. Linux has become friendlier but can still ask a little more of new users.
