IntroductionOperating system is a very important and crucial software system which can help computer to generate computer programs, because a computer without operating system cannot work well. So that the operating system can connect to the keyboard or mouse of the input device, output device such as screen or printer and control the disk drive. In large system, the operating system plays a more helpful situation in assisting different types of programs and users to run the system at the same time without interfering with each other. The operating system is also a security system that protects users from unauthorized access to the system. Operating system consists of various types, Microsoft is Microsoft Windows 7 is the most common type of operating system used in computers, 2nd is Apple MacOS, this operating system exists only within Apple computer and IOS is a system used in your Apple phone. The third is the Linux operating system, a popular variant of computers used by Linux and IBM compatible computers and Google's Android operating system, is a system used in Android compatible phones. The operating system can be classified into few types, 1 of which is multi-user and this allowed 2 or more users to run the program at the same time. The next 1 is multitasking; means that a computer can run more than 1 or 2 programs at the same time. After is multithreading, which allows different types of individual programs to run at the same time and can continue in real time as it responds instantly to input. In this report we have chosen 3 types of operating systems among Windows, Mac and Linux and will explain them further in detail. Windows Operating System The Windows operating system is established by Microsoft. The graphical user interface is a program to… middle of paper… the operating system increasingly provides more ported hardware than other operating systems and drives the operating system on servers such as mainframes and supercomputers. After multitasking is a crucial feature for Linux, it allows you to run multiple applications at the same time, which can become more useful in IT networking companies to conduct any complex work. Conclusion In the overall study of operating system, we can understand that operating system is crucial and important because it helps every business in the world to do their work with information technology. The trend of recent years of technology is rapid growth reflecting the improvement of the operating system which can be avoided. Operating system users, based on their demand and the work required, will use different types of operating system in order to maximize, effectively and efficiently perform their tasks.