Define Operating System. List out its types and explain services.

Block Diagram of Operating System

Generally, operating system works as an inter-mediator between computer and users. Actually, it is a group of software or applications that handles all the computer hardware and services of computer programs. Allocation of memory and controlling them is one of its basic service. In fact, Operating System can be categorized according to their processing nature and brand.

A. On the basis of processing nature, the types of OS are as follows:

1. Real Time OS
2. Multitasking OS
3. Network OS
4. Distributed OS
5. Batch Processing OS

Except these five, there are also other types of operating system like, multi-processing os, multi-programming os etc. However, these are the basic types of Operating System

B. On the basis of brand, the types of OS are categorized as below:

1. Windows OS
2. Iphone Operating System (IOS)
3. Android OS
4. MAC OS
5. Linux OS
6. Unix OS

These six operating systems are also common types of operating system now available or used in IT field. Among them, IOS, and Android are mostly used as operating system of Smartphones. However, windows OS is both used in smartphone and desktop or computer. MAC, Linux, Unix are mostly used in desktop. Linux and Unix are mostly preferred by network programmers. 

Services in the terms of Operating System are executing program, running IO operating, establishing communication, manipulating files, detecting errors, allocating resources, protecting data and information etc.

1) Protection of Data and Programs:

Obviously, data and information have to be protected from various viruses and malware. It is common but most essential service of an OS.

2) Resource Allocation among users and processors:

Resource allocation needs frequently if an Operating system is working on the multi-programming, multi-processing or time-sharing environment.

3) Error Debugging: 

There may be lots of bugs into a programs and application and they must be checked and corrected. Error debugging is actually a process of finding bugs and correcting. An OS must have ability of error debugging.

4) Establishing Communication: 

Nothing is possible without communication. An OS must provide communication services. It is frequently need in a distributed environment. OS routes and makes an way of establishing of communication between two systems. Communication may be between two different devices or different processes of a single system. 

5) Manipulation of Files: 

File contains collection of data and information. Files must be saved into a computer memory. Users should have facility to store, delete and update that information. And all these are made possible by operating system.

6) I/O Service: 

In a computer, users can give input, s/he can takes output for a particular purpose. There are many device drivers used in an Operating System to facilitate this service. Device driver operates a hardware on the basis of operating system. Operating system gives accessibility to that device.