software+system

=what is system software?(aleverno)= =The **operating system** and **utility programs** are the two major categories of **system software**. Just as the processor is the nucleus of the computer system, the **operating system is the nucleus of all software activity.**= =The operating system is the **most important program** that runs on a computer. Every general-purpose computer **must have** an operating system to run other programs. Operating systems perform basic tasks, such as= =It is the **first program loaded into memory** when the computer is turned on and, in a sense, **brings life to the computer hardware**. Without it, you cannot use your word processing software, spreadsheet software, or any other applications.= =Without an operating system, you **cannot communicate** with your computer. When you give the computer a command, the operating system relays the instructions to the 'brain' of the computer, called the microprocessor or CPU. You cannot speak directly to the CPU because it only understands **machine language**. When you are working in an application software program, such as Microsoft Word, commands that you give the application are **sent through the operating system** to the CPU. Windows2000, Window95/98, Mac OS, Unix and DOS are all examples of operating systems.= ==
 * =recognizing input from the keyboard=
 * =sending output to the display screen=
 * =keeping track of files and directories on the disk=
 * =controlling peripheral devices such as disk drives and printers.=