What is an operating system? 3rd semester diploma notes

Operating System

An operating system is application software. It is an interface between the user and the computer (hardware). It provides a platform for running application programs.

An operating system (OS) is a vital piece of software that serves as the core foundation and intermediary between the hardware components of a computer and the software applications that users interact with. The primary purpose of an operating system is to manage and control the various resources of a computer.

It is a control program that controls the computer components and acts as a resource allocator.

Goals of Operating System

  1. Primary Goal: To provide convenience to the user in executing the program.
  2. Secondary Goal: To use computer components efficiently.
Types of Operating System
  1. Batch Operating System
  2. Multi-programmed Operating System
  3. Multitasking Operating System
  4. Multiprocessing Operating System
  5. Real-time Operating System
  6. Distributed  Operating System
  7. Clustered Operating System
  8. Embedded Operating System

1. Batch Operating System

  • Does not interact with the computer directly.
  • The operator takes all the jobs and groups similar jobs into batches.
  • The operator takes the job as input. process it on the CPU and give the result back to the user.
  • Various mediums used are: Punch Cards, Paper Tape
Advantages of Batch Operating System
  • Multiple users can share the batch systems.
  • Less idle time {Idle time of CPU is less}
  • Managing large amounts of work is easy.
Disadvantages of Batch Operating System
  • Expert computers with knowledge of batch operating systems are needed.
  • Can be expensive.
  • Debugging is hard.
  • Other jobs need to wait for an unknown amount of time if they fail.

2. Multi-programmed Operating System

  • Increases CPU utilization by organizing jobs (code and data). So that the CPU always has one to execute. (Less idle time)
  • Keeps multiple jobs in main memory (RAM).
  • Generally non-preemptive.
  • When a process does some input or output task, the CPU can start the execution of another process.

हिंदी में पढ़ने के लिए यहाँ क्लिक करे : Click Me For Hindi!

हिंदी में पढ़ने के लिए यहाँ क्लिक करे : Click Me For Hindi!

हिंदी में पढ़ने के लिए यहाँ क्लिक करे : Click Me For Hindi!

हिंदी में पढ़ने के लिए यहाँ क्लिक करे : Click Me For Hindi!

3. Multitasking Operating System

  • It is a logical extension of multiprogramming.
  • The CPU executes multiple jobs by switching among them, typically using a small-time quantum, and the switching occurs so fast that the user feels like interacting with each executing task at the same time.
Differences between Multitasking and Multiprogramming Operating Systems
Multiprogramming OS Multitasking OS
  • Context switching is used.
  • CPU utilization is increasing.
  • The operating system simply switches to and executes another job when the current job needs to wait.
  • Context switching and time-sharing are used.
  • CPU utilization and responsiveness.
  • Switching happens when either the allowed time expires or there is another reason for the current process to wait.


4. Multiprocessing Operating System

  • More than one processor is present in the system.
  • It allows more than one process to be executed at the same time.
  • These multiple CPUs share a memory bus, memory, and devices.
  • All these devices are tightly coupled between the processors.
Types of Multiprocessing Operating System

1. Symmetric

  • One operating system controls all CPUs, and each CPU has equal rights.
  • All CPUs are in a peer-to-peer relationship.

2. Asymmetric

  • There is a master processor that gives instructions to all the other processors.
  • Master-slave relationship.
Advantages of Multiprocessing Operating System
  • Max throughput.
  • More reliable.{ A fault in one processor does not cause loss of work.}
  • Fast processing.
  • Improved Efficiency.
Disadvantages of Multiprocessing Operating System
  • It’s very complicated.
  • Memory requirements are higher.

5. Real-time Operating System

  • Serves real-time systems.
  • Are used when time requirements are very strict, like robots or traffic control.
  • The time intervals required to process and respond to inputs are very small.
Types of Real-Time Operating System

1. Soft: Less strict time constraints, e.g., multimedia systems, and digital audio systems.

2. Hard: Very strict time constraints and the shortest possible delay are also not acceptable. e.g. Robot

Advantages of a Real-Time Operating System
  • Maximum utilization of devices and systems.
  • Less time is required for task shifting.
  • More focus on running applications. {Less focus on applications in queue}.
  • Can also be used in embedded systems like transport and others.
Disadvantages of a Real-Time Operating System
  • A few tasks run at some point.
  • Heavy system resource usage.
  • The algorithms used are complex.
  • Specific device drivers and interrupt signals are needed.

6. Distributed Operating System

  • Uses many control processors to serve multiple real-time applications and users. {NODES}
  • Connects multiple computers via a single communication channel.
  • Each computer comes with its processor and memory and communicates via high-speed buses or telephone lines.
  • Also referred to as a loosely coupled system.
Advantages of Distributed Operating System
  • The failure of one node doesn’t affect the entire system.
  • Fast consumption.
  • Loss is bad for the host computer.
  • Easily Scalable.
Disadvantages of Distributed Operating System
  • Failure of the host or main network will stop communication.
  • Difficult to implement.

7. Clustered Operating System

  • Similar to a parallel system, as they also use multiple CPUs.
  • The difference is that clustered systems are made up of two or more independent systems linked together.
  • contains an independent computer system with shared storage media.
  • All systems work together to complete a task.

Types of Clustered Operating Systems

1. Software Cluster: Allows all the systems to work together.

2. Hardware Cluster: Allows high-performance disk sharing among systems.

Advantages of Clustered Operating System
  • Failure of a single node doesn’t mean a lack of services {High Availability}
  • More cost-effective and cheaper.
  • Scalability is easy.
  • Availability and performance are better than single-computer systems.
Disadvantages of Clustered Operating System
  • It necessitates the use of additional servers and hardware, making maintenance difficult.

8. Embedded Operating System

  • It is designed to perform specific tasks on a device that is not a computer. e.g., car parking {devices}, medical equipment {devices}, small devices.
  • Are designed to be small, resource-efficient, and dependable.
  • Hardware is usually quite resource-constrained.
Advantages of Embedded Operating System
  • small and fast to load.
  • Cheap
  • Easy to manage.
  • More stable and reliable.
  • Low power consumption.
Disadvantages of Embedded Operating System
  • It is hard to troubleshoot.
  • Limited memory resources.
  • You can’t change, improve, or upgrade the system once it has been developed.


What are the main functions of an operating system?

  • Resource management: The OS allocates and manages memory, CPU time, storage space, and other resources among different applications and processes.
  • Process management: The OS controls and monitors the execution of programs, ensuring that they don’t interfere with each other.
  • File management: The OS organizes and manages files and folders on storage devices.
  • Security: The OS provides mechanisms to protect the system from unauthorized access and malicious attacks.
  • User interface: The OS provides a user interface (UI) for interacting with the computer, such as a graphical user interface (GUI) or a command-line interface (CLI).

What are the different types of operating systems?

  • Desktop operating systems: These are designed for personal computers, such as Windows, macOS, and Linux.
  • Mobile operating systems: These are designed for smartphones and tablets, such as Android and iOS.
  • Server operating systems: These are designed for servers that provide services to other computers, such as Windows Server and Linux distributions like Red Hat Enterprise Linux (RHEL) and Ubuntu Server.
  • Embedded operating systems: These are designed for specific devices, such as wearables, smart TVs, and smart home devices.

What are some popular operating systems?

  • Windows is the most popular desktop OS.
  • macOS is the default operating system for Apple computers.
  • Linux is a free and open-source operating system available in various distributions.
  • Android
  • iOS is the mobile operating system used on Apple iPhones and iPads.
  • Chrome OS is a lightweight operating system based on the Chrome web browser, designed for cloud-based computing.

How do I choose the right operating system for me?

The best operating system for you depends on your needs and preferences. Some factors to consider include:

  • Your budget: Windows and macOS are typically more expensive than Linux.
  • The hardware you are using is: Make sure the operating system is compatible with your computer’s hardware.
  • The software you need to run: Make sure the operating system supports the applications you need.
  • Your level of technical expertise: Linux requires more technical knowledge than Windows or macOS.
  • Your personal preferences: Do you prefer a simple and easy-to-use interface or a more customizable experience?

What are some common operating system problems?

  • System crashes are when the operating system unexpectedly stops working.
  • Blue screen of death (BSOD): A specific error message that occurs on Windows computers.
  • Malware is malicious software that can damage your computer.
  • Driver issues: problems with the software that allows your hardware to communicate with the operating system.
  • Performance issues: slowness, freezing, and other performance problems.

How can I troubleshoot operating system problems?

  • Consult the documentation for your operating system.
  • Search online for solutions to specific problems.
  • Contact your computer manufacturer or software vendor for support.
  • Use diagnostic tools to identify problems.
  • Back up your data regularly.

Where can I learn more about operating systems?

  • Official websites of operating system vendors.
  • Online tutorials and courses.
  • Books and magazines.
  • Blogs and forums.

Leave a comment


Enjoy this blog? Please spread the word :)

Why Pink shocked as a fan throws their mother’s ashes on stage? Untold Secrets: 15 Hidden Facts About the Titanic Star’s Dies Mr. Beast beats Mark Zuckerberg, becomes first person to hit 1 million followers on Threads How to Become a Successful Google ne launch kiya new AI Tool Deseret Book, exclusive facts, hidden treasures, surprising insights, awestruck, LDS bookstore Chandrayaan-3, India’s third moon mission, successfully launched Big Monster Truck Toys Remote Control: Unleashing Epic Off-Road Adventure! 2023 BET Awards Winners List 10 Unforgettable Destinations in the USA You Need to Visit Now 10 best Amazon Prime Day tech deals on Amazon Fire Stick, Apple, Bose and more