Operating system (OS)
Also known as: OS, operating system, operating systems
An operating system (OS) is the main software that runs a computer, phone, or tablet.
It manages hardware such as memory, storage, and the screen, runs apps, handles files, and provides the interface you see, from the Windows Start menu to an iPhone home screen. Popular operating systems include Windows, macOS, Linux, ChromeOS, iOS, and Android. While most people rarely think about their OS, it decides which apps you can run and how long your device stays secure through updates.
Operating system (OS), explained at three levels
At home
An operating system is like the manager of a busy restaurant. It decides which cook uses which station, keeps everything organized, and makes sure customers get served.
At work
The operating system determines which business software staff can use and how devices are secured and managed.
At home
Your OS gets regular updates with security fixes and new features. When a device stops getting OS updates, it becomes riskier to use online.
At work
Each OS has its own management tools, such as Microsoft Intune for Windows, Apple Business Manager for Macs and iPhones, and Android Enterprise. Mixed environments need a strategy for each.
At home
Switching operating systems means relearning habits and possibly buying new apps. In my opinion, it's worth it only if your current one truly doesn't fit your needs.
At work
Track OS versions and end-of-support dates in asset inventories, plan upgrades before deadlines, test line-of-business apps on new versions, and limit the number of OS platforms to reduce support complexity.
Real-world examples
At home
Sophie's tablet stopped getting operating system updates. Her bank's app eventually stopped working on it, so she replaced it with a newer model.
At work
Marcus manages devices for a Calgary dental practice. He keeps an inventory of every computer's OS version and end-of-support date so upgrades never sneak up on him.
How it compares
| feature | Windows | macOS | Linux |
|---|---|---|---|
| Main devices | PCs and laptops | Macs | Servers, PCs, embedded |
| Made by | Microsoft | Apple | Open-source community |
| Cost | Licence, often included | Included with Macs | Usually free |
| Software choice | Widest | Wide | Narrower for desktop apps |
Each OS balances compatibility, control, and cost differently.
For analysts
In any system rollout, I'd confirm supported operating systems early. Discovering late that key staff use an unsupported OS can derail a project.
History & origin
Early computers in the 1950s ran one program at a time, loaded by hand. IBM's OS/360 in the mid-1960s and Unix, created at Bell Labs in 1969 by Ken Thompson and Dennis Ritchie, shaped modern operating systems. Microsoft's MS-DOS powered the IBM PC from 1981, and Apple's Macintosh in 1984 popularized graphical interfaces, followed by Windows. Linux arrived in 1991, Apple's Mac OS X, based on NeXT's Unix-like system, in 2001, and iOS and Android brought operating systems to phones from 2007 and 2008. Today, Android runs on more devices than any other OS, while Windows dominates desktops. In my view, choosing an operating system is really choosing an ecosystem of apps, accessories, and services.