<Tr> <Td> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> </Td> </Tr> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> An operating system (OS) is system software that manages computer hardware and software resources and provides common services for computer programs . All computer programs, excluding firmware, require an operating system to function . </P> <P> Time - sharing operating systems schedule tasks for efficient use of the system and may also include accounting software for cost allocation of processor time, mass storage, printing, and other resources . </P>

What is an operating system explain its functions
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