What are the Types of Operating System ?
Based on the capabilities and the types of application supported, the operating system can be divided into six major categories viz.
1. Batch Processing Operating System
They are capable of executing only one job at a time. The jobs a program submitted by different users are grouped into batches and one batch of the job is to provide as input to the computer system at a time. The jobs in the batch are processed on a first come first serve basis. After execution of one job is completed the operating system automatically fetches the next job from the batch without any human intervention.
- a) They were very efficient in their time as idle time for these computers is very less.
- b) The OS facilitates execution of jobs in an organized manner.
- a) Jobs are processed only in the order they are places and not per user’s priority.
- b) Debugging of a program at execution is not possible.
- c) The executing jobs may enter an infinite loop as each job is not associated with proper times.
2. Multi-user Operating System
The multi-user operating system enables multiple users to use the resource of a computer system at the same time. It allows a number of users to work simultaneously on the same computer.
It is usually implemented by following multiterminal configuration. In the configuration, a single powerful computer is connected to multiple terminals through serial ports.
The computer system is responsible for processing different requests generated by various terminals at a time. The control computer is equipped with a fast processor and a memory of large capacity for catering to multiple requests of end-users.
Example: Linux, Unix, VM-386, etc.
- a) Allows resources of a computer to be utilized in an inefficient manner.
- b) It enhances the overall productivity of various users by providing simultaneous access to various computer resources.
- a) It is complex and hence difficult to handle and maintain.
- b) It may result in inconsistent data if activities of a user aren’t protected from other users.
- c) It is required to have a robust security mechanism.
3. Multitasking Operating System
The multitasking operating system allows users to carry out multiple tasks at the same time on a single computer system.
The multitasking OS are also known as several other names such as multi-processing, multiprogramming, concurrent, or process scheduling operating system. In this type of operating system, different processes are executed simultaneously by implementing the concept of time slicing.
According to this concept, a regular slice of CPU time is provided to each of the processes running in the computer system. It can be of two types, viz.
a) Preemptive Multitasking Operating System
In this OS, a slice of CPU time is allocated on some priority basis.
b) Co-operative Multitasking Operating System
In this OS, time slices of CPU are assigned to the process depending on whether or not to give up CPU control for other running processes.
Example: UNIX, Windows 2000, Linux, Windows XP.
- a) It helps in increasing the overall performance of the system.
- b) It helps in increasing the overall productivity of the user by performing a number of tasks at the same time.
- a) A large amount of memory is required to execute several programs at a time.
- b) Some mechanisms need to be implemented to ensure that the activity of one process does not interfere with the activities of other processes.
4. Rest- time Operating System
The real-time operating system is similar to the multi-tasking operating system in its functionality. However, these OS are specially designed and developed for handling real-time applications or embedded applications.
The real-time applications are those critical applications that are required to be executed within a specific period of time.
Examples of real-time applications is; industrial robots, space-crafts, industrial control applications.
It is of two types, viz.
a) Head Real-time OS
It is a type of OS where it is necessary to perform a task in a specified amount of time.
b) Soft Real-time OS
In Soft Real-time OS, a task can be performed even after its allocated time has elapsed.
Example: M tox, Lynx, RTX
- a) It is easy to design, develop and execute the real-time application under the real-time OS.
- b) It is usually more compact as compared to other operating systems hence requires less memory.
- a) It is primarily focused on optimizing the execution time of an application and thus it sometimes overlooks some of the other critical factors related to the overall efficiency of the computer system.
- b) It is used only for providing some dedicated functionality and cannot be used as a general-purpose OS.
5. Multiprocessor Operating System
Multiprocessor OS allows the use of multiple CPUs in a computer system for execution of multiple processes at the same time. The processes are executed faster compared to a single processor.
Example: Linux, UNIX, Windows 2000, etc.
- a) It helps in improving the overall efficiency and throughput of a computer system.
- b) It helps in increasing the reliability of a computer. If one CPU fails, the other CPU takes control and executes the currently running processes.
- a) Cost is very high.
- b) A large amount of memory is required for running and executing several users programs.
6. Embedded Operating System
It is somewhat similar to the real-time OS. The embedded OS is installed on an embedded computer system which is used for performing a computational task in electronic devices.
This OS provides limited functionality that is required for the corresponding embedded computer system.
Example: Palm OS, Window CE.
- a) It allows the implementation of an embedded system in an efficient manner.
- b) A system with an embedded OS is easy to use and maintain.
- a) It is possible to perform some specific operation with those OS.
- b) This OS cannot be used in a frequently changing environment.