Difference Between Single User and Multiuser Operating System

The operating system’s reason for existence is to serve the end-users by using the hardware resources. The operating system can be designed to serve the need of the single superuser or to serve the need of multiple users using the same computer resources. 

The function of the operating system is to fulfill the requirements of the application programs of the computer to function properly because these application programs are used to interact with the end-user. Also, the way the operating system fulfills the requirements of these application programs determines whether the operating system is designed for a single user or multiple users. 

What is the difference between a single user and multi user operating system? (Tabular Form)

Single User Operating System	Multi User Operating System
In a Single-User Operating System, only one user can access the computer at the same time.	In a Multi-User Operating System, more than one user can access a computer at the same time.
The bootloader loads all the resources of the CPU in the profile of a single superuser.	The bootloader distributes the resources of the CPU based on the priority of the users.
A Single Super User is allocated all the resources of the CPU, and only the super user controls the operating system.	The Concept of Super User Does not exist, instead, role-based entities exist, such that, upper roles hierarchy can manage the lower roles hierarchy permission and settings.
As all the resources are dedicated to a single superuser, therefore, faster processing of instruction in the operating system occurs.	The resources are divided among multiple users therefore the processing slower processing of instructions in the operating system occurs.
The Single User Operating systems are simplistic and easy to design.	The Multi User Operating systems are complicated as they have to apply complex techniques to share the resources among various users.
The types of Single User Operating systems are – Single-User Single-Task Operating systems and Single-User Multi-Task Operating systems.	The types of Multi-User Operating System are – Time Sharing Operating System and Distributed Operating System.
Examples of Single User Operating Systems are – MS DOS, Windows 95, Windows NT, Windows 2000, Personal Computers, etc.	Examples of Multi User Operating Systems are Mainframes such as IBM AS400, Linux & Unix Distributed OS, etc.

What is single user operating system?

The operating system can serve the needs of the single user by allotting all the permission to one superuser and the operating system loads all the application programs into the account of that superuser and all this process is taken care of by the bootloader. The bootloader is responsible for the loading of the operating system on the hardware during the booting of the computer system. During the time of booting up, the bootloader loads all the facilities of the operating system into the account of that superuser. 

The single-user operating system is generally found in homes and offices where only one user can utilize the operating system at one point in time. There are also two types of the single-user operating system, they are 

1. Single-User Single-Task Operating System, and 
2. Single-User Multi-Task Operating System

Single-User Single-Task Operating System

The single task operating system can only handle one application program that is used by the end-user. The CPU does not support the vector processing method which supports the multi-user. Also, as only one program can function at the same time, therefore, all the processing power is being used to serve that particular program hence the faster execution of the programs. 

These types of operating systems are more used in domain-specific industries where computers have only one function to perform and all the processing power is allotted to that function. 

Single-User Multi-Task Operating System

The Multi-Task operating system is found in homes and offices and can perform the processing of many application programs at the same time. For example, a person can be listening to music and typing the article on MS word and also running an update in the background and all these functions can be processed at the same point of time and this is also called multi-tasking functionalities of the operating system. 

This multitasking functionality uses the method of parallel processing. In Parallel Processing, the CPU processors are arranged in a specific interconnection where the instructions can be divided and processed by multiple processors, and then the outputs are combined and provided to the operating system to store in the memory device, similar to the divide and conquer technique. 

Examples of Single User operating system

1. MS-DOS 
2. Palm OS
3. Windows 95
4. Windows NT Workstation
5. Windows 2000 professional

What is multi user operating system?

The multi-user operating system can serve multiple end-users at the same point in time. The operating system manages the hardware resources such as memory and CPU in such a way that the task of one user does not affect the task of some other user. 

The two types of multi-user operating systems are –

1. Time-sharing operating system and 
2. Distributed operating system. 

Time-Sharing Operating System 

In the time-sharing operating system, each user is allocated a short span of CPU time. In this short span of time, the user can perform the execution of their process by utilizing the CPU resources. The time span is very short (in nanoseconds) and to the eyes of the users, it seems that execution is being processed continuously.

An example of the time-sharing operating system is the mainframe where the user is allocated a specific time to complete their task.

Distributed Operating System

The distributed operating system is another term for a computer network that supports far away users to use the resources which are present in some remote location.

The Distributed System divides the resources in such a way that multiple requests can be handled and each request can be satisfied eventually.

The distributed operating system can be used in electronic banking, multiplayer gaming apps, etc

Examples of Multi User operating system

1. All linux based OS
2. Windows 10
3. IBM AS400
4. Ubuntu
5. macOS
6. Unix