PC maintenance is the practice of ensuring the smooth functioning and longevity of personal computers. It involves tasks like hardware checks, software updates, and system optimization. Operating systems (OS) serve as the core software that manages a computer's resources and user interaction. They include Windows, macOS, and Linux. Understanding and maintaining an OS is crucial for efficient PC operation. Regular maintenance and a good grasp of OS fundamentals are key to keeping computers secure, responsive, and reliable in our digital age.