Which description best defines a desktop operating system?

• A. Operating system installed on a single computer, referred to as PCs
• B. A system that runs on multiple servers
• C. An operating system used only for mobile devices
• D. A type of software that protects your files with encryption

Answer: (A)

A desktop operating system is the software that runs on a single personal computer, managing the hardware and software on that machine and providing the graphical interface and core services you interact with, like files, apps, and devices. It’s designed for a single computer used directly by a person, typically referred to as a PC. That’s why the description saying it’s installed on one computer—the PC—best fits. Desktop OSs include Windows, macOS, and Linux desktop editions, and they focus on productivity and user interaction on a single workstation.

The other ideas describe different things: running on many servers points to server operating systems for networks or data centers; mobile devices use their own class of operating systems optimized for phones and tablets; encryption software is a security tool, not an OS.