1.2. What Is a Computer?
A computer is a device capable of performing computations and making logical decisions at speeds millions (even billions) of times faster than human beings can. For example, many of today’s personal computers can perform several billion calculations in one second. A person operating a desk calculator could not perform that many calculations in a life-time. (Points to ponder: How would you know whether the person added the numbers correctly? How would you know whether the computer added the numbers correctly?) Today’s fastest supercomputers are already performing trillions of instructions per second!
Computers process data under the control of sets of instructions called computer programs. These programs guide the computer ...
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