Operating system

Operating system - Introduction An operating system (OS) is an integrated set of programs that controls overall resources such as CPU, memory, input-output device of the computer system. The major objective of operating system is to improve the performance and efficiency of a computer system. Like the manager of a company, an operating system is responsible for the smooth and efficient functioning of the entire computer system. The operating system provides the platform for other application program/software to run and execute. It provides user with an interface so that user can easily communicate with computers, which is more convenient to use and operate. An operating system is a collection of programs that controls the overall operation of the computer system. It also controls and co-ordinate the use of hardware, among the various application program for various user. So, it acts as an interface between user and the computer hardware. The other major functions of operating system are: -It controls, monitor and co-ordinate overall operation of our computer system. -It acts as an interface between user and computer. -It provides platform to develop, run and execute other computer program. -It manages hardware resources such as CPU, memories, input-output terminals, networking equipment etc. -It hides programming and hardware complexity to the user. The primary goal of an operating system is to maximize the productivity of a computer system by operating it in most efficient manner and maintaining the amount of human intervention. Some examples of operating system are: MS-DOS, Windows, LINUX, MACOS, UNIX, Chrome, Fedora, Ubuntu etc.

Functions / Features / Advantages of Operating System (OS) - V.imp
1) Input-Output (I/O) Management: Input-Output is essential to operate any computer. It allows computer to interact with several peripheral devices such as keyboard, mouse, printer, scanner etc.

2) User Interface (UI): User Interface means an ideal environment in which user can work on it so that s/he can interact with the computerized system. Every operating system provides the feature of user interface in order to enhance the experience and joy of using computer or any other computerized system. It act as a bridge between user and computer. There are 2 types of user Interface.
Character/Command User Interface (CUI): Eg MS-DOS
Graphical User Interface (GUI): Eg Windows, MAC OS

3) Security: The operating system of a computer has a number of built-in tools to protect against security threats such as viruses, unauthorized access, suspicious network activity etc. The basic security in a OS is to control access to your computer by setting users and password.

4) Process Management: The process management allocates a processor to execute a chosen process. OS acts as a traffic controller, job scheduler, process scheduler and dispatcher.

5) Memory Management: Memory is a large array of bytes, each with its own address. When the user request CPU for read-write operation. OS determines the amount of memory required for the program instruction and data. Then OS allocates required memory to load the program and data into RAM. When the program terminates it frees up the space and new program is loaded.

6) Data Management: Data management allows organizing their data into logical grouping called files. Earlier Operating system does not provide features of data management. Hence, they were inflexible but nowadays, every operating system provides this feature.

7) Command Interpreter: The command interpreter reads the command that a user types in at a terminal, interprets them and translate them into detail set of instruction that computer hardware can understand. Every operating system must have command interpreter for its operation.

8) Dead-Lock prevention: During processing a situation can arise in which a resource shared by two or more process cannot continue because the resources required by a process is held by other. This situation is known as dead lock. For eg. If process-1 allocates resources A and later required resources B and process-2 allocates resources B and later requires resources A. In this situation neither process-1 nor process-2 will be executed. Such situation is called deadlock. Operating system ensure prevention of deadlock by taking situation action by careful allocation of resources.

9) Time sharing: The function of OS that involves CPU to allocate time in a number of users on same computer. This property generally found in network operating system such as windows NT.

10) Virtual Memory: Virtual memory is the feature of an operating system that allows a computer to compensate for shortage of physical memory by transferring temporary files from RAM to disk. Virtual memory has twice as many addresses as main memory. The process of translating virtual address into real address is known as mapping. The copying of virtual pages from disk to main memory is swapping.