If I have to explain an operating system to a Lyman I would use this
analogy "An operating system is like a manager. Its job is to make sure
that all of the programs on the computer are doing their job". Setting
aside the Lyman terms the actual definition of an operating system is
"Operating System is in charge of making sure the system operates
correctly and efficiently in an easy-to-use manner".
The purpose of an operating system is to
organize and control hardware and software so that the device it lives in
behaves in a flexible but predictable way. In this article, we'll tell you what
a piece of software must do to be called an operating system, show you how the
operating system in your desktop computer works and give you some examples of
how to take control of the other operating systems around you.