TYPES OF OPERATING SYSTEM

Types of Operating System (OS)

 

Following are the popular types of Operating System:

 

1.      Batch Operating System

 

2.      Multitasking/Time Sharing OS

 

3.      Multiprocessing OS

 

4.      Real Time OS

 

5.      Distributed OS

 

6.      Network OS

 

7.      Mobile OS

 

1. Batch Operating System

 

Some computer processes are very lengthy and time-consuming. To speed the same process, a job with a similar type of needs are batched together and run as a group.

 

The user of a batch operating system never directly interacts with the computer. In this type of OS, every user prepares his or her job on an offline device like a punch card and submits it to the computer operator.

 

2. Multi-Tasking/Time-sharing Operating systems

 

Time-sharing operating system enables people located at a different terminal (studl) use a single computer system at the same time. The processor time (CPU) which is shared among multiple users is termed as time sharing.

 

3. Multiprocessing OS

 

It has two or more processors for a single running process. Processing takes place in parallel and is also called parallel processing. Each processor works on different parts of the same task, or, on two or more different tasks. Since execution takes place in parallel, they are used for high speed execution, and to increase the power of computer, Linux, UNIX and Windows 7 are examples of multiprocessing OS.

 

3, Real time OS

 

A real time operating system time interval to process and respond to inputs is very small. Examples: Military Software Systems, Space Software Systems are the Real time OS example.

 

4. Distributed Operating System

 

Distributed systems use many processors located in different machines to provide very fast computation to its users.

 

 5. Network Operating System

 

Network Operating System runs on a server. It provides the capability to serve to manage data, user, groups, security, application, and other networking functions.

 

6. Mobile OS

 

Mobile operating systems are those OS which is especially that are designed to power smartphones, tablets, and wearables devices.

 

Some most famous mobile operating systems are Android and iOS, but others include BlackBerry, Web, and watchOS.

 

4.4.2 Services

 

An Operating System provides services to both the users and to the programs.

 

·         It provides programs an environment to execute.

 

·         It provides users the services to execute the programs in a convenient manner.

 

Following are a few common services provided by an operating system

 

1.      Program execution

 

2.      1/0 operations

 

3.      File System manipulation

 

4.      Communication

 

5.      Error Detection

 

6.      Resource Allocation

 

7.      Protection

 

1. Program execution

 

Operating systems handle many kinds of activities from user programs to system programs like printer spooler, name servers, file server, etc. Each of these activities is encapsulated. as a process.

 

A process includes the complete execution context (code to execute, data to manipulate, registers, OS resources in use). Following are the major activities of an operating system with respect to program management -

 

·         Loads a program into memory.

 

·         Executes the program.

 

·         Handles program's execution.

 

·         Provides a mechanism for process synchronization.

 

·         Provides a mechanism for process communication.

 

·         Provides a mechanism for deadlock handling.

 

2. 1/0 Operation

 

An I/O subsystem comprises of I/O devices and their corresponding driver software. Drivers hide the peculiarities of specific hardware devices from the users.

 

An Operating System manages the communication between user and device drivers.

 

1/0 operation means read or write operation with any file or any specific I/O device.

 

·         Operating system provides the access to the required I/O device when required.

 

 

3. File system manipulation

 

A file represents a collection of related information. Computers can store files on the disk (secondary storage), for long-term storage purpose. Examples of storage media include magnetic tape, magnetic disk and optical disk drives like CD, DVD. Each of these media has its own properties like speed, capacity, data transfer rate and data access methods.

 

A file system is normally organized into directories for easy navigation and usage These directories may contain files and other directions. Following are the major activities of an operating system with respect to file management

 

·         Program needs to read a file or write a file.

 

·         The operating system gives the permission to the program for operation on file

 

·         Operating System provides an interface to the user to create/delete files.

 

·         Operating System provides an interface to the user to create/delete directories

 

·         Operating System provides an interface to create the backup of file system.

 

4. Communication

 

In case of distributed systems which are a collection of processors that do not share memory, peripheral devices, or a clock, the operating system manages communications between all the processes. Multiple processes communicate with one another through communication lines in the network.

 

The OS handles routing and connection strategies, and the problems of contention and security. Following are the major activities of an operating system with respect to communication

 

·         Two processes often require data to be transferred between them

 

·         Both the processes can be on one computer or on different computers, but are connected through a computer network.

 

·         Communication may be implemented by two methods, either by Shared Memory or by Message Passing.

 

5. Error handling

 

Errors can occur anytime and anywhere. An error may occur in CPU, in I/O devices or in the memory hardware. Following are the major activities of an operating system with respect to error handling -

 

·         The OS constantly checks for possible errors.

 

·         The OS takes an appropriate action to ensure correct and consistent computing.

 

 

6. Resource Management

 

In case of multi-user or multi-tasking environment, resources such as main memory, CPU cycles and files storage are to be allocated to each user or job. Following are the major activities of an operating system with respect to resource management -

 

·         The OS manages all kinds of resources using schedulers.

 

·         CPU scheduling algorithms are used for better utilization of CPU.

 

7. Protection

 

Considering a computer system having multiple users and concurrent execution of multiple processes, the various processes must be protected from each other's activities.

 

Protection refers to a mechanism or a way to control the access of programs, processes, or users to the resources defined by a computer system. Following are the major activities of an operating system with respect to protection

 

·         The OS ensures that all access to system resources is controlled.

 

·         The OS ensures that external I/O devices are protected from invalid access attempts.

 

·         The OS provides authentication features for each user by means of passwords.