A computer is a tool and partner in every sphere of human life and activity. Computers are bringing many changes in industry, government, education, medicine, scientific research, law, social service and even arts like music, movies and paintings. The areas of application of computers are confined only by the limitation on creativity and imagination.
What is a computer? A child might define a computer to be an instrument capable of producing a combined effect of radio, movie and television. This definition is close but still does not visualize the power and capabilities of a computer.
A computer is an electronic machine, capable of performing basic operations like addition, subtraction, multiplication, division, etc. The computer is also capable of storing information, which can be used later. It can process millions of instructions in a few seconds and at the same time with high accuracy. Hence a computer can be defined as an automatic electronic machine for performing calculations or controlling operations that are expressible in numerical or logical terms. Computers are very accurate and save time by performing the assigned task very fast. They don’t get bored. Humans have always needed to perform arithmetic like counting and adding. During the pre-historic period, they counted either on their fingers or by scratching marks on the bones and then with the help of stone, pebble and beads. The early civilization had witnessed men develop number systems to keep track of the astronomical cycles, businesses, etc. The word ‘computing’ means ‘an act of calculating’. After the invention of the manual calculating tools, the concept of using ‘electronic gadgets’ for computations were introduced which gave birth to the computers. The evolution of computers has passed through a number of stages before reaching the present state of development. During the early development period, certain machines had been developed and a brief note of them is given below.