What are the Different Types of Operating Systems?

1. Single user operating system:-

In single user operating system one user can operate only one system. We can not run more than one application at a time, if you want to run another program, we have to close the current application or program. The best example for single user operating system is MS Dos. 

2. Multi user operating system:

The name itself suggest that, this operating system allows many users to work at any instant of time. 

Here many users are connected to different monitors. A multiuser operating system can have hundreds of users at any point of time and keeping track of every events. Its requires large amount of RAM. 

Here the computer gives a user his time and goes to another user giving his quota of time and shifts to another and this process goes on. 

3. Batch processing:- 

Operating system executes various tasks and request’s in batches not as individual task these operating system accepts various tasks from the user and places them in queue waiting execution. This process of placing request’s in a queue for execution is known as spooling. Each job task is assigned a priority, where execution time is available then these jobs are selected on the basis of their priority from the queue. 

4. Interactive O/S: 

Interactive O/S do provide for features where the user can directly interact with the computer from a terminal. The user can interrupt the execution of high priority batch job and get his low priority job done by the computer. Most of the main frame based O/S today use these interactive O/S. 

5. Multi tasking O/S:- 

A running state of program is called a process or a task. Multitasking O/S is a type of multi program O/S which can perform several processes simultaneously. The earliest multi tasking O/S available to home users was the amigo O/S. All current major O/S support this feature. 

6. Multi programming O/S:-

In multi programming O/S several number of programs are feed into main memory of the computer and processed. 

• ˜The multi programming O/S runs one program at a time. When the program requires some I/O operation which is slow process the CPU switches to another job for execution. 
• ˜ If the second job also requires I/O operation the C.P.U switches to third job and so on.
• ˜Always a program will be in one of the 3 states ready, running and blocked. 
• ˜ Until the first program completes I/O operation it is blocked and once completed the C.P.U switches back to it. 
• ˜Multi programming is the inter leaved execution of 2 or more separate and independent programs by the same computer. 

7. Multi processing O/S : - 

Multi-processing refers to the ability of a system to support more than one processor at the same time. Applications in a multi-processing system are broken to smaller routines that run independently. The operating system allocates these threads to the processors improving performance of the system.