Commonly Used Operating Systems

What Even Is an Operating System?

You’ve probably used a computer or a phone today. You clicked things, watched videos, maybe typed something — and it all just worked. But have you ever wondered what’s actually running the show behind the scenes?

That invisible layer is called an operating system, or OS for short.

Think of it this way: your computer’s hardware — the screen, keyboard, memory, processor — is like the body of a car. It has all the parts, but on its own it doesn’t know how to drive. The operating system is like the engine management system and dashboard controls combined: it brings everything to life and gives you a way to interact with it.

More concretely, an operating system does three main jobs:

Manages hardware — It talks directly to your CPU, RAM, storage, and other components so that your apps don’t have to. Every app just asks the OS: “hey, I need some memory” or “please save this file,” and the OS handles the dirty work.
Runs programs — When you double-click an app, the OS loads it, gives it resources, and keeps it running. It also makes sure multiple apps can share the computer at the same time without crashing into each other.
Gives you a user interface — The desktop, the taskbar, the file explorer, the windows — all of that is part of the OS. It’s what you see and click on.

Without an OS, your computer would just be an expensive pile of silicon and plastic that does nothing when you press the power button.

Commonly Used Operating Systems

Windows

Made by: Microsoft
First released: 1985
Most common version today: Windows 11

Windows is by far the most widely used desktop operating system in the world. If you’ve ever used a school computer, a library computer, or a family PC, there’s a very good chance it was running Windows.

What makes Windows recognizable?

The Start Menu — that button in the bottom-left corner (or center in Windows 11) that opens a launcher for all your apps.
The taskbar — the bar at the bottom showing your open apps and system tray.
File Explorer — the app you use to browse your files and folders.

Why do people use Windows?

Huge software compatibility — almost every piece of software ever written runs on Windows. Games, creative tools, business apps — you name it.
Wide hardware support — Windows runs on laptops and desktops made by hundreds of different manufacturers: Dell, HP, ASUS, Lenovo, and more.
Familiar to most people — because it’s so common, most people already know how to use it.

Any downsides?

Windows is sometimes criticized for being more prone to viruses if not maintained properly, and it can feel cluttered with pre-installed apps you never asked for. It also requires a license (though most PCs come with it included).

macOS

Made by: Apple
First released: 2001
Most common version today: macOS Sequoia (2024)

macOS is the operating system that runs on Apple’s Mac computers — MacBooks, Mac Minis, iMac desktops, and Mac Studios. It’s known for its clean, polished design and tight integration with Apple’s ecosystem.

What makes macOS recognizable?

The Dock — a row of app icons sitting at the bottom (or side) of the screen, always within reach.
The Menu Bar — a thin bar at the very top of the screen that changes depending on which app you’re using.
Spotlight Search — press ⌘ Space and a search bar pops up. You can launch apps, search files, do math, and more — all without touching the mouse.

Why do people use macOS?

Smooth design — macOS is famous for looking and feeling polished. Animations are smooth, fonts are crisp, and the whole thing feels intentional.
Great for creative work — video editors, musicians, designers, and developers tend to love Macs. Apps like Final Cut Pro and Logic Pro are macOS-exclusive.
Apple ecosystem — if you also have an iPhone or iPad, your Mac works seamlessly with them. You can answer iPhone calls on your Mac, copy something on your phone and paste it on your laptop, and more.
Unix-based under the hood — macOS is built on a Unix foundation, which makes it popular among developers who appreciate a powerful terminal.

Any downsides?

macOS only runs on Apple hardware, which is generally more expensive than comparable Windows machines. You also have less flexibility to customize the system, since Apple tightly controls the experience.

Linux

Made by: The open-source community (originally started by Linus Torvalds in 1991)
Most common versions (called “distributions”): Ubuntu, Fedora, Debian, Arch Linux

Linux is different from Windows and macOS in a fundamental way: it’s open source. That means anyone can look at its code, modify it, and redistribute it — for free. Because of this, Linux comes in many flavors called distributions (or “distros”), each with a different look, feel, and purpose.

What makes Linux recognizable?

That’s the tricky part — Linux doesn’t have one single look. Some distros look like Windows, some look like macOS, and some are completely unique. The common thread is that Linux gives you a lot more control over your system than the others.

Most Linux distros do share:

A desktop environment (like GNOME or KDE Plasma) that determines the visual style.
A terminal — a text-based way to control your computer, which Linux users tend to use heavily.
A package manager — a built-in app store-like tool for installing software from the command line.

Why do people use Linux?

It’s free — no license fees, ever.
Highly customizable — you can make it look and behave almost any way you want.
Lightweight — some Linux distros run smoothly on very old hardware that would struggle with Windows or macOS.
Beloved by developers and engineers — most web servers, cloud systems, and supercomputers run Linux. Learning it early is a big career advantage.
Privacy-friendly — Linux doesn’t collect your data the way Windows or macOS might.

Any downsides?

Linux has a steeper learning curve. Some popular software (like Microsoft Office or Adobe Photoshop) doesn’t officially support Linux, though workarounds exist. If you just want something that “works out of the box,” Windows or macOS might be easier to start with.

Comparing the Three

	Windows	macOS	Linux
Cost	Paid (usually bundled)	Paid (Apple hardware required)	Free
Hardware	Any PC	Apple only	Any PC
Customization	Limited	Very limited	Extensive
Software compatibility	Widest	Good	Varies
Best for	Gaming, general use	Creative work, Apple users	Developers, privacy-focused users
Open source?	No	No	Yes

Wait — Your Phone Has an OS Too

Here’s something that might surprise you: every smartphone also runs an operating system. You’ve been using one this whole time without thinking about it much — and that’s kind of the point. Mobile operating systems are designed to stay out of your way.

Android

Made by: Google
Powers: Samsung, Google Pixel, OnePlus, Xiaomi, and most other Android phones

Android is the most used mobile OS in the world. It’s based on Linux (yes, really!) and is open source at its core, which is why so many different phone manufacturers can use and customize it. Samsung’s “One UI,” for example, is just Android dressed up in Samsung’s own style.

You’re using Android’s OS every time you swipe down for notifications, open the app drawer, or install something from the Google Play Store.

iOS

Made by: Apple
Powers: iPhone and iPod Touch

iOS is Apple’s mobile operating system, and like macOS, it’s exclusive to Apple hardware. It’s known for being very smooth, secure, and tightly integrated with the rest of Apple’s ecosystem.

You’re using iOS every time you tap the home button, swipe between apps, or open the App Store on an iPhone.

Why don’t people “feel” the mobile OS as much?

On a desktop, the OS is very visible — you see the desktop, the taskbar, the file system. On a phone, the experience is designed to feel more like a stream of apps than a “computer.” The OS hides itself. But it’s still doing the same fundamental job: managing hardware, running apps, and giving you an interface.

Summary

An operating system is the software that makes a computer usable. It sits between the hardware and the user, managing resources and giving you an interface to interact with.

Windows — the most common desktop OS, great for gaming and general use.
macOS — Apple’s polished OS, beloved by creatives and developers.
Linux — a free, open-source OS that’s incredibly flexible and powers most of the internet.
Android — the most used mobile OS, built on Linux, runs on most smartphones.
iOS — Apple’s mobile OS, exclusive to iPhones, known for smoothness and security.

Every time you turn on a device, the OS is the first thing that wakes up — before any of your apps, before your wallpaper, before anything. It’s the foundation everything else is built on.