Definition-Explanation of Operating System and Role of Operating System:
Definition and Explanation:
An operating system is a program that acts as an interface between the user of computer and the hardware. The purpose of an operating system is to provide an environment in which a user may execute programs.
An operating system is an important part of almost every computer system. A computer system can roughly be divided into three components:
Hardware: Hardware provides basic computing resources. It includes memory, CPU, arithmetic-logic unit, various storage devices, I/O, peripheral devices etc.
Systems Programs: System programs manage the use of hardware among various application programs for various users. System programs include operating system, compilers, editors, loaders, utilities etc,
Application Programs: Application programs define the ways in which system resources are used to solve computing problems of the users. Application programs include database systems, business programs etc.
Users: The users include people, machines and other computers.
The central processing unit (CPU) is located on chips inside system unit. CPU is the brain of computer. This is the place where computer interprets and processes information.
The operating system is the important component of the systems programs. Systems programs are directly executed on computer hardware. It enables application programmers and other users to access the power of computer fully and efficiently.
Systems programming is different from application programming. It requires deeper knowledge of computer hardware. The system programs are often large and more complex. System programs provide the foundation on which the application programs are built. So the systems programs must be reliable, efficient and correct.
Role of Operating System:
The hardware provides the basic computing resources in a computer system. The applications programs define the way in which these resources are used to solve computing problems of the users. The operating system controls and coordinates the use of the hardware among various systems programs and application programs for various users.
The role of operating system can be defined in the following ways:
1. Government:
Operating system works as a government. The basic resources of computer system are provided by its hardware, software and data. It performs no useful function on its own. It actually provides the means and the environment for proper use of its resources.
2. Resource Allocator:
A computer system has many resources. Each resource can be used to solve a problem. The operating system is responsible for managing the use of system resources. There may be many requests for a particular resource. These requests may be conflicting. The operating system decides which request should obtain the required resource. The operating system should take into consideration both system efficiency and fairness to individual requests.
3. Control Program:
An operating system is a control program that prevents errors. It ensures that the system resources are not used improperly.
There is no completely adequate definition of what is part of the operating system and what is not. Some people consider that text editors and other utility programs provided by the vendor is part of operating system. A more generally accepted definition of the operating system is that it is the program that is running at all times on the computer. This program is usually small and is commonly known to as kernel. Anything that is not part of the kernel is an application program.
The primary goal of an operating system is convenience for user. Operating systems exist because they make it easier to compute. This is particularly clear when you look at operating system for small personal computers.
A secondary goal is the efficient operation of a computer system. It is particularly important for large, shared multi-user systems. Operating systems can solve this goal. It is known that sometimes these two goals, convenience and efficiency, are contradictory.
An operating system is a group of programs designed to serve two basic purposes:
1. To control the allocation and use of the computing system's resources among the various users and tasks.
2. To provide an interface between the computer hardware and the programmer. The programmers create code, debug and maintain application programs.
An effective operating system should accomplish all of the following tasks:
- Facilitate creation and modification of program and data files through an editor program.
- Provide access to compilers to translate programs from high-level languages to machine language.
- Provide a loader program to move the complied program code to the computer's memory for execution.
- Provide routines that handle the complicated details of I/O programming
- Assure that when there are several active processes in the computer, each will get fair chance to get the CPU.
- Take care of storage and device allocation.
- Provide for long term storage of user information in the form of files.
- Permit system resources to be shared among users when appropriate, and be protected from unauthorized or mischievous intervention as necessary.
Systems programs like translators and utility programs are not usually considered part of operating system. An operating system is responsible for providing access to these system resources.
