Operating System Overview

What is an Operating Systems?

Operating System is a collection of system programs which control the operation of computer systems. It provides the facility of managing hardware resources and services to access these resources in an effective manner. Commonly a computer system consists of five major components. They are hardware, operating system, system programs, application programs and the users. Actual work is carried out by the hardware which includes memory, central processing unit, and input/output devices as well. Operating system provides a set of services to programs and users interact indirectly with the operating system though the programs. System programs provide a set of utility programs which include with the operating system to provide basic functions to the user and finally application programs provide facility for user requirements.

Operating Systems Objective

As the operating system connects software and hardware with each other there are three objectives in an operating system.

• Convenience
• Efficiency
• Ability to evolve

Convenience

The hardware and software used to provide applications to the user can be viewed in the following layered or hierarchical fashion. The end user as well as other users of these applications do not concern with the details of the computer hardware. Therefore end users view a computer system in terms of a set of applications. Hence an application programmer can be expressed as an application by using a programming language. The most important system program is the operating system. As the operating system mask the details of the hardware (functionality of the hardware) from the programmer and provide a convenient interface for using the system in an effective manner.

Efficiency

A computer is a collection of resources which will be able to move, store and process data and to control of these functions. As a result of this operating system is responsible for managing these resources. Operating system is also a set of computer programs. But the key difference between other programs and the operating system is that operating systems guide the processor in resource management and scheduling of other programs. Therefore operating system manages all the resources which attached to the computer and improves the efficiency of using the system.

Ability to evolve

Due to different reasons operating system evolve over time. Some of them are described below.

• Hardware upgrades plus new types of hardware: The improvement of the hardware such as graphics terminals affected the design of operating systems.

• New services: in response to user demand or in response to the needs of system managers, operating system extend to offer new services.
  
  
• Fixes: operating system faults are discovered over time. Therefore

  these faults should be corrected.