Compose a 8000 words essay on The role of OS. Needs to be plagiarism free! Some of the most common functionalities of any operating system are mentioned below:History of Operating Systems starts as early as the first computing machine. It is a subject of great researched and every generation is adding more features to the operating system making them more and more efficient. The modern operating systems can be broadly classified into two categories:Microsoft Windows is the most common household operating system widely present. Its success mainly is a result of its user interface which is very user friendly. Windows has a graphical user interface which makes it very easy for the user to select options and issue commands. XP was the latest success of the Windows family. The user interacts with the hardware in form of buttons, boxes and images by clicking the mouse. Any layman without any experience working with computers can easily work on GUI based operating systems.UNIX on the other hand is an operating system which is not GUI based. Users working on UNIX have to remember commands and type the commands to achieve results. Although UNIX is quite popular on the research front, it did not gain wide acceptability because of the lack of a graphical user interface.There is no well defined fact as to which operati… There is no well defined fact as to which operating system is better than the other. Every OS has its own disciples and haters. Every commercially available OS has its own pros and cons. Microsoft operating systems are easy to use but are expensive and low on security. Linux and UNIX on the other hand are freely available and extremely secure but lack a user friendly user interface. It depends on the type of the user and his nature of requirements that finally decides which OS would be the best for him.Answer 2An Operating System acts an interface between the user and the computer. Although most users would have had some experience with an operating system, it is very difficult to precisely define the purpose of an operating system. This difficulty arrives mainly due to the fact that an operating system performs two basically unrelated functions: Extended Machine and Resource Manager (Tanenbaum, 1987). As an extended machine the operating system assists the architectural components (Instruction Set, Memory, IO) to understand the user input, provides them with their requirements to solve the user problem and give the result back to the user. As a resource manager the Operating System provides the users with a top-down view. The operating System performs the job of controlled and orderly allocation of processors, memory and IO devices among the various tasks that are competing for them.Based on the above discussion the primary purposes of an Operating System can be enlisted as under:Process Management: Process is defined as an instance of a program that is currently under execution (Stallings, 2002). A process needs certain resources such as CPU time, memory, files and IO devices to accomplish its tasks.