About 7,130,000 results
Operating system - Wikipedia
What is an Operating System? - GeeksforGeeks
Operating System (OS) Definition & Examples - Lifewire
Operating System Tutorial - GeeksforGeeks
Computer Basics: Understanding Operating Systems
Find information about your device - Microsoft Support
Operating system (OS) | Definition, Examples, & Concepts
What is an operating system (OS)? - TechTarget
What is an Operating System? - How-To Geek
Operating System - Overview - Online Tutorials Library