Besides the application software and compiler software, there is a third kind of software, called the operating system, which is very important for the working of the PC.
When a user wants to store any data or program, the data or program is stored at a location that is known only to the operating system. Therefore, the operating system performs the task of storage management.
Besides storage management, the operating system also performs device management. For instance, when a user wants to print information on the printer, or display information on the VDU, he or she does not have to bother about the actual transportation of the information from the internal storage to the VDU or to the printer. The operating system takes care of it.