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Systems programs and systems programmers – a possible source of confusion Different computer programs do different things. A common way to classify software is whether they are applications or system programs. However, in the use of the term ‘system’ here is not in the general way a system has been described earlier in this unit. When the term ‘system’ is used to refer to a system program or systems programmer the reference is to the software that is closely related to the operating system of a particular computer. For example, the Windows 95 disk formatting software is a systems program; it is not an example of the type of system we are most interested in. (Unfortunately, the world of computing and software development is full of such confusing terms.) So system programs perform tasks that are inherently to do with the operating system (parts of the system like computer viruses, sound volume, window and memory management). Examples of system programs include: background virus checker, soundcard volume controller, window managers, print manager, process scheduler, backup utility An application program (often just called an application) is usually short running and helps the user perform a task not-directly related to a particular computer system. Examples include: writing a letter in a word processor, playing a game, calculating an invoice in a spreadsheet, searching for information in a database. By long running it is meant that system software tends to be started when the computer is switched on, and may run continuously until the computer is switched off. Or certainly system software might run for a longer period than when the user starts and terminates one or more applications (e.g. imaging printing a 1000-page book, the user could do tasks with many different applications while the print manager ensures pages are sent to the printer regularly). By short running it is meant that an application might be started up halfway through a computer session, used for, say, 5 minutes and then terminated when the user decides to do some other task. Application programs are so called since they allow the user to ‘apply’ the computer to help perform some real-world task. In the same way that programs are categorised into systems programs and application programs, the programmers of such software are also categorised, i.e. into systems programmers and application programmers.
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