examples of an operating system
DOS (Disk Operating System) was the first widely-installed operating system for personal computers.
GUI - Short for Graphical User Interface, a GUI Operating System contains graphics and icons and is commonly navigated by using a computer mouse.
Multi-user - A multi-user operating system allows for multiple users to use the same computer at the same time and different times.
Multiprocessing - An operating system capable of supporting and utilizing more than one computer processor.