Introduction:
The primary purpose of an operating system is to make the most efficient use of the computer hardware. It serves as an intermediary between the user and the computer hardware, enabling the user to interact with the computer system and providing an environment for executing applications.

Efficient use of computer hardware:
The operating system is responsible for managing the computer's resources and ensuring their efficient utilization. It allocates CPU time, memory, and other hardware resources to different processes and applications running on the system. By efficiently managing these resources, the operating system ensures that the computer system operates at its optimal performance.

Resource allocation:
The operating system uses various scheduling algorithms to allocate CPU time to different processes based on their priority and requirements. It also manages the memory by allocating and deallocating memory space to different processes as needed. Additionally, the operating system handles input/output operations, manages storage devices, and controls the execution of programs.

Hardware abstraction:
One of the key functions of an operating system is to provide hardware abstraction. It hides the underlying complexities of the hardware and presents a simplified interface to the user and application programs. This abstraction allows users to interact with the computer system without having to understand the intricate details of the hardware. For example, the operating system provides a user-friendly graphical user interface (GUI) that allows users to interact with applications using icons, menus, and windows.

Device management:
The operating system manages various input/output devices such as keyboards, mice, printers, and network interfaces. It provides device drivers that enable these devices to communicate with the computer system. The operating system handles device interrupts, manages device queues, and ensures smooth data transfer between devices and memory.

Conclusion:
In summary, the primary purpose of an operating system is to make the most efficient use of the computer hardware. It achieves this by managing system resources, providing hardware abstraction, and facilitating user interaction. By efficiently utilizing the computer's resources, the operating system ensures optimal performance and enables users to effectively use the computer system.