The essential part of a computer
The operating system is a low-level software that supports a computer's basic functions. It is the software that manages computer hardware and software resources. Application programs usually require an operating system to function.It manages the sharing of memory between multiple applications.It handles input and output to and from attached hardware devices, such as hard disks, printers.
An operating system can manage how to divide the program so that it runs on more than one processor at a time. The operating system determines which applications should run in what order and how much time should be allowed for each application before giving another application a turn.
The picture above is of some operating systems.