*WHAT IS IT*
The role of operation
he operating system underpins the entire operation of the modern computer.
Abstraction of hardware
The fundamental operation of the operating system (OS) is to abstract the hardware to the programmer and user. The operating system provides generic interfaces to services provided by the underlying hardware.
In a world without operating systems, every programmer would need to know the most intimate details of the underlying hardware to get anything to run. Worse still, their programs would not run on other hardware, even if that hardware has only slight differences.