Computer systems consist in part of hardware that controls the overall activity of the computer. But in order for hardware to function, it must have the necessary instructions. These instructions are supplied by software. There are different kinds of software, each of which serves a specified purpose. Some software is necessary to make the computer operate. Another kind enables the computer to perform specific tasks. Still other software exists solely for entertainment purposes.

Operating System Software

The operating system software makes the computer perform its basic operational functions. Disk operating system (DOS) is one of the earlier types of operating system software used to power IBM-compatible computers. Commands are typed at a prompt to direct the computer to carry out its functions.

Windows is the most common operating system today. It permits several programs to be opened simultaneously and provides ease of movement between the open programs.

Windows...