The history of computer science began long before the modern discipline of computer science that emerged in the 20th century, and hinted at in the centuries prior. The progression, from mechanical inventions and mathematical theories towards the modern concepts and machines, formed a major academic field and the basis of a massive worldwide industry. The man behind the thought of this great invention was a British professor of mathematics named Charles Babez. In 1830, he designed a machine named “Analytical Engine” which had common sides with the present structure of computer. Then step by step, computer got its current shape through various procedure and research.
In terms of working criteria, there are three kinds of computers. These are analog, digital and hybrid. The analog computer works by chronologically counting of shifting figures and the digital computer works by using mathematical methods and counting electric waves. The hybrid computer is a combination of the above two; it works by using both characteristics of analog and the digital. According to the size, space and working capacity, there are four variations of digital computer: super computer, mainframe computer, mini-frame computer and micro computer.
The total figure of computer is divided into three main units: input unit, central processing unit (CPU), output unit. The input unit receives the data and delivers to memory, memory stores it for the time being and the arithmetic logic unit defines it and directs to process it with necessary programs and delivers the result to output unit to present and memory stores the result permanently if needed. The whole procedure is executed by the control unit. The arithmetic logic