Difference Between Multiprogramming And Multitasking Explained!

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Just like a nervous system controls our body, a computer is controlled by an operating system - and it performs several critical functions, including multiprogramming and multitasking. There are several differences between multitasking and multiprogramming, but before we dig into that, let's understand what exactly is an operating system. 

An operating system is the most important software that controls computer hardware and other software programs. The user cannot execute commands directly from the CPU in machine language, and the CPU cannot communicate directly with the user. As a result, the operating system is required to communicate between the user and the CPU.

The operating system acts as a middleman that translates all interaction between the user and the CPU. In simple words, it is the heart of our computer and not only manages basic tasks such as managing peripheral devices, displaying screens, and tracking data and files but also performs advanced functions such as multiprogramming and multi-tasking.

Multiprogramming is the ability of more than one user to operate a computer while using a single CPU. The idea is to successfully use the processor to create multiple ready-to-run functions with each function belonging to the different users. Multitasking means the simultaneous implementation of multiple processes per user on the same computer using multiple CPUs. 

What Is Multiprogramming?

In a modern computer system, there are usually multiple programs waiting to be executed. It is now the responsibility of the modern operating system to manage all processes efficiently and effectively. These processes are also known as functions.

Therefore one of the most important features of the Operating System is to perform multiple programs.

Now, the main memory is too small to carry all the processes or functions. Thus, these processes are initially stored in an area called the job pool. This workspace contains all those processes that anticipate the allocation of core memory and CPU.

How does a multi-programmed system work?

In a multi-programmed system, the CPU selects a function from all the waiting functions and starts performing it. When the process needs to wait for any IO operation then the CPU switches to another active process and starts executing it. It is also known as the concept of context switching. This context switching mechanism keeps the CPU busy and active all the time and reduces CPU idle time. It can be done with slower CPU processing. It requires a small amount of memory (RAM or ROM) to operate.

Objective: The multiprogramming objective is to allow more processes to run at the same time and keep the CPU busy for as long as possible and simply focus on maximizing CPU utilization or CPU time.

Advantages of Multiprogramming Operating System

• High CPU utilization.
• Shorter response time.
• Shorter waiting time.
• Increased throughput.
• It may be extended to multiple users.
• It has the ability to assign priority to different processes.

Disadvantages of Multiprogramming Operating System

• Scheduling implementation is not easy.
• Memory management is necessary because all types of functions are stored in the main memory.
• It must keep track of all kinds of processes it is concurrently running.

What Is Multitasking?

Multitasking is quite similar to multiprogramming but in this, the CPU is allocated to process for fixed timing which is 'Time Quantum / Time Slice'. After that CPU 'Context Switch' to another process. It's basically a logical extension of multiprogramming. It thus processes multiple tasks by using a single resource. 

While in multiprogramming, multiple programs run simultaneously, in multitasking a single program is divided into multiple tasks that can run concurrently. Multitasking operating systems are also known as time-sharing operating systems.

How does a multi-tasked system work?

In a multitasking operating system, each process is executed for a fixed period of time, and after that time CPU is switched to another process. This principle of time slice is called time quantum. The switching between processes is so fast that it gives an illusion to the user that all the processes are running at the same time but actually, it doesn't happen. In multitasking, a single program is split into tasks. The tasks can run simultaneously using a single resource, but multiple programs do not run at the same time. 

For instance, you are using your computer and listening to songs, and at the same time, you are scrolling through Instagram feeds and chatting on WhatsApp web. It seems to you like all the functions are happening at the same time but actually, they are not. It's just the job processing time is faster than in multiprogramming and the processor is switching between different jobs in such a fast manner that we think that they are happening at the same time. 

Objective of Multitasking: The main objective of multitasking is to reduce the response time of the system and to support user interaction with the system. 

Advantages of Multitasking Operating System

• It has a shorter response time as compared to Multi Programming system.
• It can handle multiple users concurrently, and several programs can run smoothly without affecting the system’s performance.
• Users can use multiple applications such as Internet browser, PowerPoint, MS Excel, games, and other resources at once.
• It allows multiple users to share common resources concurrently.
• It provides logical parallelism.

Disadvantages of Multitasking Operating System

• It is complex to implement.
• It can't be executed on a slow-speed processor.

Multiprogramming Vs Multitasking

Here are the key differences between multiprogramming and multitasking: 

Both of these terms are often used collectively to represent the modern operating system but have different purposes and functions. While a Multi Programming system operating system allows more than one system to run simultaneously using a single processor, a Multi-Tasking operating system allows multiple processes or tasks to be performed simultaneously using multiple CPUs.

Multi Programming is bringing multiple processes into the main memory and then executing them one after the other on a single processor. On the other hand Multitasking operating system executes more than one process at the same time utilizing multiple CPUs on the same computer. Multi Programming uses the concept of context switching and tries to attain maximum CPU utilization while Multitasking uses the concept of time-sharing to improve CPU reaction time and provides a high degree of parallelism.