System Software

System software (or systems software) is computer software designed to operate and control the computer hardware and to provide a platform for running application software.
System software includes the following:
The operating system (prominent examples being z/OS, Microsoft Windows, Mac OS X and Linux), allows the parts of a computer to work together by performing tasks like transferring data between memory and disks or rendering output onto a display device. It also provides a platform to run high-level system software and application software.
Utility software helps to analyze, configure, optimize and maintain the computer.
Device drivers such as computer BIOS and device firmware provide basic functionality to operate and control the hardware connected to or built into the computer.
Window systems are components of a graphical user interface (GUI), and more specifically of a desktop environment, which supports the implementation of window managers, and provides basic support for graphics hardware, pointing devices such as mouse, and keyboards. The mouse cursor is also generally drawn by the windowing system.
In some publications, the term system software also includes software development tools (like a compiler, linker or debugger).
In contrast to system software, software that allows users to do things like create text documents, play games, listen to music, or surf the web is called application software.