An operating system

What is an operating system? What is the main function of the command interpreter? In Operating Systems, which of the following is/are CPU scheduling algorithms? To access the services of the operating system, the interface is provided by the ? CPU scheduling is the basis Which one of the following is not true? Which one of the following errors will be handle by the operating system? Where is the operating system placed in the memory? fails, most operating system write the error information to a ?Which one of the following is not a real time operating system?