If you are a programmer, chances are you are well-versed with the terms; multiprogramming, multitasking, multithreading, and multiprocessing. These terms play a vital role in multiprogramming operating systems.

The terms may sound familiar but did you know they differ from each other in various aspects? But, before digging into their differences, let’s understand what these terms mean.


Whenever multiple programs reside in the main memory or simply more than a single program resides in the main memory, this situation is called multiprogramming. In multiprogramming, once the currently executed program is sent off, the execution and work on the next program start immediately. This is done when the multiprogramming operating system sends the next task to the CPU. 

You can get most work from the CPU by engaging it in back-to-back program execution. In certain cases where a specific program asks for input or output resources, the other programs lying in the main memory are sent to the CPU for maximum work done. 

This way multiprogramming operating systems offers maximum efficiency and quick resolving of requests by the users. 


Multiprocessing is a setup where a single system or a device is connected to different or multiple processors at the same time. These multiple processors work on the execution of the task together running on the system. Simply put, every system is connected to different processing units to increase overall efficiency and reduce the time in program execution. 

 It can be done in two different ways. The first method is the symmetric method where the main operating system remains on a single processor whereas the other processors are consumed in the execution of the program required by the user. The second way is via the asymmetric method where any of the processors are available, the operating system will reside on that. 


Multithreading is a unique and very specific process where every main process or program is divided into smaller parts or sub-processes known as threads. These threads are nothing but the convenient breakdown of the main program to increase efficiency. 

However, none of the threads are dependent on the execution of the other one. Each thread is executed with a unique execution path. Although, each thread is in some way connected to the other thread in terms of internal communication. 

But what exactly is the thread? Well, the thread is a trail through which you can execute a process easily by dividing it into parts. Every thread has a unique and individual program counter, register, and stack that makes it highly exclusive. Since threads are part of the whole process, they are very light weighted and can be easily processed by the processors. 


As the name suggests, multitasking is a process of handling and executing various tasks at once by the processor. The processor is sent various tasks by the user back to back which are executed simultaneously. Multitasking is a term used for the ability of the operating system to handle and execute various tasks at the same time. While executing these tasks, the CPU switches between various jobs and gets the processes done faster. Multitasking also helps to resolve the thrashing in OS issues. 

Also, there are two ways in which you can categorize the multitasking process. The first one is single-user multitasking which is a process of handling multiple tasks given by a single user. However, the second method is multi-user multitasking where the processor receives tasks. 

Now you understand these terms, let's understand the basic differences between them based on parameters.

Based on the number Of CPUs

 A multiprogramming operating system only allows one CPU at a time. On the other hand, Multi processing system allows multiple or several processors i.e. CPUs while working. Whereas, you can perform multithreading with one or multiple processors depending on the situation and your choice. This system only consists of a single CPU throughout the process.

Based on efficiency

The efficiency of a multiprogramming system is lesser than other systems. However, multithreading provides moderate or usual efficiency but doesn’t match the efficiency offered by multiprocessing. Out of the 4 processes, multiprocessing provides maximum efficiency and resolves the issues with minimum time. Multitasking also provides usual efficiency which is lower than multiprocessing but higher than multiprogramming.

Based on the number of users

Multiprocessing can be done by one or multiple users at the same time. But multiprogramming can only be done by a single user at a given instant. Multithreading is usually done by a single user whereas multitasking is always done by multiple users at the same time which makes it highly convenient and timesaving.

Based on economic convenience

Multithreading and multitasking are highly economical and provide excellent results at a cheaper price than usual. Whereas multi-processing is a bit expensive and cannot be categorized as economical. However, the overall efficiency accounts for the expense. 

Based on processes 

A multiprogramming system only processes one process at a time which makes it quite time-consuming and inefficient if you have different processes running. However, multithreading covers various threads or parts of a single process at the same time which makes it easier yet the overall time taken to complete various processes will be higher.

 While multi-processing you can complete various processors at the same time making it one of the best systems to execute multiple processes in a lesser amount of time. Multitasking also executes only a single job at a time but since the process is faster your overall number of processes will be done sooner.

Based on the time taken 

Multiprocessing requires less amount of time to process a single job. This is because the processors can handle various jobs at the same time. However, multiprogramming requires a higher amount of time to process or execute a certain job. You will have to sit back and relax for multiprogramming to work.

 Multithreading and multitasking take moderate time in completing the job processed on the system. They take higher time than multiprocessing but lesser time than multiprogramming.


Multiprogramming, multiprocessing, multitasking, and multithreading systems come with different advantages and disadvantages associated with the total working of each system. 

You can choose an appropriate system wisely only after analyzing each one of them individually. Make sure you understand the difference between each system to establish a clear picture of what you need and what these systems can do for you.