- Operating System Tutorial
- OS - Home
- OS - Needs
- OS - Overview
- OS - History
- OS - Components
- OS - Structure
- OS - Architecture
- OS - TAT & WAT
- OS - Types
- OS - Services
- OS - Properties
- OS - Processes
- OS - Process Scheduling
- OS - Scheduling algorithms
- OS - Multi-threading
- OS - Memory Management
- OS - Virtual Memory
- OS - I/O Hardware
- OS - I/O Software
- OS - File System
- OS - Security
- OS - Linux
- OS - Exams Questions with Answers
- OS - Exams Questions with Answers
- Operating System Useful Resources
- OS - Quick Guide
- OS - Useful Resources
- OS - Discussion
Operating System - Needs
An Operating System is a software which helps applications softwards, system softwares to intertact with computer's hardware. Operating System manages a system's hardware and other resources and performs basic tasks like file management, memory management, process management, input/output handling, peripheral device management like disk drives, printers, speakers etc.
Most popular Operating Systems in Computers include Windows, Linux, Unix and in Mobiles, Android and iOS.
Need for an Operation System
An Operating System is an essential part of any computer software. Without Operating System, we cannot even operate a computer. The primary purpose of an Operating System is to enable applications (softwares) to interact with a computer's hardware and to manage a system's hardware and software resources. Following are some of the salient features of an Operating System which can help us to understand the need of an operating system.
Interface between User and Computer
An Operating System provides an interface between user and a computer. For example, Windows Operating System provides a GUI, Graphical User Interface where a user can visually interact with computers by clicking icons, typing words using keyboard, using mouse to perform many actions on a computer. Similarly Unix provides a command line interface, where a user can type command to perform a particular operation.
Booting Process
When a computer is switched on, there is no application in main memory. First Operating System is loaded in main memory which then assist user to log on to the machine. This initial startup of a computer or mobile device is known as booting process. Without Operating System, booting cannot happen.
Managing Input/Output Devices
A computer has multiple peripheral devices like mouse, keyboard, speakers, scanner, printers. Operating System manages all of these devices connected to the computer. It assists in installing the device drivers. For example, windows operating system provides a control panel to manage all hardware devices, to check their health. It also provides options to troubleshoot if any device is not functioning properly.
Multitasking Support
An operating system, in a multitasking environment, ensures that each task or precisely a process gets its CPU share when it needs to do some computation while other process can be busy in I/O operation, like writing to primary or secondary memory or waiting for user input or writing to printer and so on. This way, with the help of Operating System, a user can perform multiple tasks simultaneously on a computer like listening music while working on word document, browse web and keep multiple application open in system so that any application can be opened in its current state.
Platform for Application Softwares
Operating System provides an environment to Application Softwares to execute. Application softwares need not to know about underlying machine language. They are intended for a particular Operating System. For example, a Word document software for Windows will not work on Linux machine. Operating System provides many services like I/O operations, file system manipulation, resource allocation and protection.
Memory Management
Operating system manages primary memory and disk. Operating System can increase available physical memory via virtual memory management. It moves processes back and forth between main memory and disk during a program execution. Via memory management, operating system keeps track of each and every memory location, being allocated to some process or being free and allocates memory accordingly.
System Files Management
Operating System provides control and interface to create/delete files, directories in underlying file system on disk. It provides permission management like to give readonly or read-write permission to files or directories or to show/hide them. An operating sytstem also provides options to create backup of files and to restore them when needed.
Security Management
Operating System provides many security features to safeguard system and its resources. It ensures that all access to system resources is controlled. External I/O devices are protected from invalid access attempts and an Operating System provides authentication features for each user by means of passwords or other ways of authenticating a user.
Error Management
Errors can occur anytime and anywhere. For example, an error may occur during a CPU operation, performing I/O operations on devices or in the memory hardware. Operating System takes care of such issues by constantly checking for possible errors and by taking an appropriate action to ensure correct and consistent computing.