Theory - 95 :- Operating System

Operating System

An Operating system (OS) is a software which acts as an interface between the end user and computer hardware. Every computer must have at least one OS to run other programs. Applications like Chrome, MS Word, Games, etc needs some environment in which it will run and perform its task. The OS helps you to communicate with the computer without knowing how to speak the computer's language. It is not possible for the user to use any computer or mobile device without having an operating system.

Function of an Operating System

In an operating system software performs each of the function:

1. Process management:- Process management helps OS to create and delete processes. It also provides mechanisms for synchronization and communication among processes.
2. Memory management:- Memory management module performs the task of allocation and de[1]allocation of memory space to programs in need of this resources.
3. File management:- It manages all the file-related activities such as organization storage, retrieval, naming, sharing, and protection of files.
4. Device Management: Device management keeps tracks of all devices. This module also responsible for this task is known as the I/O controller. It also performs the task of allocation and de-allocation of the devices.
5. I/O System Management: One of the main objects of any OS is to hide the peculiarities of those hardware devices from the user.
6. Secondary-Storage Management: Systems have several levels of storage which includes primary storage, secondary storage, and cache storage. Instructions and data must be stored in primary storage or cache so that a running program can reference it.
7. Security:- Security module protects the data and information of a computer system against malware threat and authorized access. 
8. Command interpretation: This module is interpreting commands given by the and acting system resources to process that commands.
9. Networking: A distributed system is a group of processors which do not share memory, hardware devices, or a clock. The processors communicate with one another through the network.
10. Job accounting: Keeping track of time & resource used by various job and users.
11. Communication management: Coordination and assignment of compilers, interpreters, and another software resource of the various users of the computer systems. 
    
    
    

Types of Operating system:

Some of the widely used operating systems are as follows:

1. Single-user: It is an operating system in which the user can manage one thing at a time effectively.
2. Multi-user: It is a computer operating system which allows multiple users to access the single system with one operating system on it. It is generally used on large mainframe computers.
3. Multi-processing: This OS supports running a program on more than one CPU.
4. Multitasking: This type allows more than one program to run simultaneously.
5. Multithreading: Such an operating system allows different parts of a single program to run parallel.
6. Real time: These operating systems are used when there are time requirements are very strict like missile systems, air traffic control systems, robots etc.