Operating Systems
An operating system is a special kind of computer program that manages a computer's resources, and is the first program to run automatically when the computer starts. In practice, it's the platform that's preinstalled on a computer when you buy it from the store.
Features
We use an operating system for its features and functionality — without one, a computer is unusable, apart from installing one. (This does happen: on a freshly built PC, or a professional server bought bare.)
A handful of features show up in essentially every operating system, even though the implementation and underlying encoding differ from one to the next:
| Feature | Description |
|---|---|
| File system | A database used to organize data storage |
| Graphic system | Used to display information on screen |
| Network | Used for communication between computers |
| Device drivers | Used for managing internal and external devices |
| Tools | Utility programs for managing files, folders, and configuration |
| Applications | User-created programs or scripts |
| Package managers | Used to install and uninstall programs |
Popular Systems
By overall popularity: Windows, Linux, macOS, Chrome OS, Android, and FreeBSD. Windows and macOS each ship as one product with tiered features by price; Linux is the outlier, available as dozens of distinct distributions built on the same kernel, each tuned for a different use case.
This page covers operating systems as a general concept. For a deep, practical dive into Linux specifically — boot sequence, file systems, permissions, distributions, and the command line — see Linux Systems in the TechOps roadmap.