What Is an Operating System?
An operating system (OS) is software that starts up a computer and keeps it running and responding to your commands. Operating systems have several important jobs. An operating system
Runs applications (useful programs like word processors, calculators, and so on) and enables you to interact with them.
Creates and maintains the user interface that you see onscreen, such as the icons you click and the dialog boxes you see.
Controls and manages the file storage system, so you can save and open data files in your applications and manage the files that run your applications.
Communicates with the hardware, giving it instructions to accomplish the tasks you request, such as printing your work.
Don’t look to the operating system for fun or productivity — that’s not its job. For example, you can’t use it to produce a newsletter, send an email, draw a picture, or look something up online. However, the operating system contributes to all those activities because it enables applications to run that can do all those things.