System Software:
System software consists of programs that manage the hardware resources of a computer and
perform required information processing tasks. These programs are divided into three classes:
the operating system, system support, and system development.
The operating system provides services such as a user interface, file and database access, and
interfaces to communication systems such as Internet protocols. The primary purpose of this
software is to keep the system operating in an efficient manner while allowing the users access
to the system.
System support software provides system utilities and other operating services. Examples of
system utilities are sort programs and disk format programs. Operating services consists of
programs that provide performance statistics for the operational staff and security monitors to
protect the system and data.
The last system software category ,system development software, includes the language
translators that convert programs into machine language for execution ,debugging tools to
ensure that the programs are error free and computer assisted software engineering(CASE)
systems.
Application software
Application software is broken in to two classes :general-purpose software and application
specific software. General purpose software is purchased from a software developer and can
be used for more than one application. Examples of general purpose software include word
processors ,database management systems ,and computer aided design systems. They are
labeled general purpose because they can solve a variety of user computing problems.
Application –specific software can be used only for its intended purpose.
A general ledger system used by accountants and a material requirements planning system
used by a manufacturing organization are examples of application-specific software. They can
be used only for the task for which they were designed they cannot be used for other
generalized tasks.
The relation ship between system and application software is shown in fig-2.In this figure, each
circle represents an interface point .The inner core is hard ware. The user is represented by the
out layer. To work with the system,the typical user uses some form of application software. The
application software in turn interacts with the operating system ,which is apart of the system
software layer. The system software provides the direct interaction with the hard ware. The
opening at the bottom of the figure is the path followed by the user who interacts directly with
the operating system when necessary.