Contents  Digital and analog computers  Characteristics of computer—Speed, accuracy, diligence, storage capability, versatility  History of computer—Calculating machines, Napier’s bones, slide rule, Pascal's adding and subtraction machine, Leibniz's multiplication and dividing machine, punch card system, Babbage's analytical engine, Hollerith's punched card tabulating machine  Generations of computer o First generation (1940 to 1956): Using vacuum tubes o Second generation (1956 to 1963): Using transistors o Third generation (1964 to 1971): Using integrated circuits o Fourth generation (1971 to present): Using microprocessors o Fifth generation (present and next): Using artificial intelligence  Classification of computer—Microcomputers (desktop computer or Personal Computer (PC), notebook computers or laptop, netbook, tablet computer, handheld computer or Personal Digital Assistant (PDA), smart phones), minicomputers, mainframe computers, supercomputers )  The computer system—Hardware, software, data, users  The Input-process-output concept  Components of computer hardware—Input/output unit, central processing unit,storage unit  Application of computers—Education, entertainment, sports, advertising, medicine, science and engineering, government, home