Imagination power of human being is very high. I salute all those scientists, who are the originators of various concepts in this universe. To create is the act of imagination. We know that Charles Babbage is very well known as father of computer. He had given birth to world’s first computer. Though, the computer born that time was a mechanical computer, it was the start of a new era of human being. If we see in recent years this computing technology has reached higher and higher with the imagination power of human being. Every machine needs some force to drive it. As computer is also a machine, it also requires something to drive it. That’s what an operating system is! In initial stage of computers they were evolved from mechanical to electromechanical then from analog electronics to digital electronics. Today our computer lives in strong world of digital electronics. But it was the requirement of generations of computer to evolve from such stages. At every stage, computer required certain force to drive it, to make it useful to human kind, to make the tasks simpler. The changing forces of computer had given birth to the generations of computer operating system, which is software today that drives the computer system. Several complicated process and algorithms are involved in the generations of the computer operating systems. As it is said that need gives birth to the inventions. The same is applicable to operating system also. So, today operating systems of the computer are approaching with various novel technologies removing more percentage of bugs from computer systems. When computers were in the generation of vacuum tubes, they needed the electronic circuits to drive it. Almost for two decades this process was continued. When transistors were introduced to the computing world, novel concept of batch system was used to drive the computers to achieve the final aim. In computing world, the new technologies are introduced to achieve the efficient output with faster speed. As hardware technology changes, it also forces to change the software technology. Batch system was the necessity of computing world when they entered in faster world of transistors from vacuum tubes. Third generation gave birth to the multiprogramming concept. This was the first time, computers were used to process more than one tasks at a time. If we see today, every system is multitasking system. Motivational concepts in these generations were used by many of the computer developers, researchers and scientists. World’s first successful operating system UNIX was born in this third generation of computer systems. Still today, it has the same significance that it was having that time. Many companies and research institutes such as AT&T Bell, IBM has great contribution to develop the force to drive the computer systems. UNIX is the operating system which has motivated many of computer researchers to work in this field and develop new concepts. We are in forth generations of computer as well as its operating system. The force now drives the personal computers today. We are watching the competition between the operating system which are open source and which are not. But, as the engineer is considered, he always chooses the operating system which is open source. So he can study, learn and accordingly design newer concepts in this field. Hope, this blog will be much useful for those who work in this field. Or this can give you certain motivation to work on newer operating systems.