A computer is an electronic machine, operating under the control of instructions stored in its own memory, that can accept data, manipulate the data according to specified rules, produce results, and store the results for future use. Computers process data to create information. Data is a collection of raw unprocessed facts, figures, and symbols. Information is data that is organized, meaningful, and useful. To process data into information, a computer uses hardware and software. Hardware is the electric, electronic, and mechanical equipment that makes up a computer. Software is the series of instructions that tells the hardware how to perform tasks. Characteristics of Computers
1> Automatic: Requires human intervention to start any task, solve problem but once initiated, it continues the job until its completed. 2> Speed: in terms of microseconds (10 power -6), nanoseconds(10 power -9), and even picoseconds (10 power -12). A powerful computer is capable of performing several billions simple arithmetic operations per second. Limited by hardware and software resources. 3> Accuracy: garbage-in-garbage-out (GIGO). E.g. Human input error, programmer logic error. 4> Diligence: Unlike human beings, a computer is free from monotony, tiredness, and lack of concentration.
5> Versatility: Can perform multiple tasks at same time. Limited by hardware and software resources. 6> Power of Remembering: As long as user desires, it can store any amount and type of information. Limited by hardware and software resources. No IQ: Cannot make decisions until instructed. Cannot learn on its own. No Feelings: No emotions, no taste, no knowledge. Instructions are required.
1.2 Evolution of Computers
Necessity is the mother of invention then who is the father? - Curiosity, Vision, Idea
1642: Pascal invented first mechanical adding machine
1671: Baron Gottfried Wilhelm von Leibniz first calculator...