Computers  and the Internet

DURING THE 1980S, PERSONAL COMPUTING BOOMED INTO A HOBBY. BY THE mid-1990s, these machines, which had been esoteric to most people only a generation before, were common electronic appliances in households, businesses, and government agencies at all levels. Computers are used for communications, word processing, data processing,  arithmetic and mathematical calculations, drawing, photo processing, mu- sic composition,  radio location, radio navigation, information searches, robot control, and many other purposes.
There are 2 major lines of personal and small-business computers: IBM (Inter- national Business Machines) -compatible and Macintosh (called as the Mac). There are other, less well known systems. Regardless of line, however, all computers have similar components.  The given figure shows is a block diagram showing major parts of a characteristic small computer system, such as the kind you may buy for the personal or small business use.