What is Computer?

The word computer means to compute or to calculate. So a computer is normally considered to be a calculating device.

But, more than 85% of the work done by computer today is of non-mathematical. Hence, a computer may be defined as a device that operates upon data or information. So computer can be defined as a machine in which we can

  • Store data or information,
  • Process data or information,
  • Retrieve data or information

With our requirements

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System Analysis and Design – I

THE SYSTEM CONCEPT

The term “system” is used in many different ways. Everyone is familiar with such expressions as “Professor Rajneesh has an impossible grading system”. or  “Deepak has a great system for managing friends.” But for computer users, a system is a group of parts that are integrated for the purpose of achieving some objective. The following three characteristics are key:

  1. A group of parts. A system has more then one element. A steering wheel is not a system, but it’s a vital part of a familiar system called an automobile.
  2. Integrated parts. A logical relationship must exist between the parts of a system. Mechanical and electronic system, such as washing machines and video games, have many components that work together.
  3. A common purpose of achieving some objective. The system is designed to accomplish one or more goals. All system elements should be tied together and controlled so that the system goal is achieved.

Since a computer is a group of integrated parts that have the common purpose of performing the operations called for in the program being executed, it qualifies as a system.

DEFINITION

The term system is derived from the Greek word systema, which means an organized relationship among functioning units or components. A system exists because it is designed to achieve one or more objectives.  A system is an orderly  grouping of interdependent components linked together according to a plan to achieve a specific objective.  The word component may refer to physical parts, managerial steps or a subsystem in a multi-level structure.

In our daily life,  the word “System”  comes across many a times but seldom the word is understood in its fullest sense. Almost every one of us have heard about Systems such as Education System, Economic System, Office System, Solar System. But what do they imply in the real sense is a  main question.

Systems could be man-made such as education system, office systems etc., or a natural system such as solar system.

We would be dealing with man-made systems. These man-made systems have certain inputs which are processed and the result is certain outputs.

Figure 1 : System

In education system, the main input is new students where they undergo the process of education and the output is a educated student.

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