What is the computer

  • 24 марта 2011 г.
  • 1278 Слова
The term computer is used to describe a device made up of a combination of electronic and electromechanical (part electronic and part mechanical) components. Computer has no intelligence by itself and is referred to as hardware. It means that hardware is the computer's physical electronic and mechanical parts. A computer system can be viewed as consisting of five mostvital elements:
• Hardware
• Software
• People
• Procedures
• Data
When one computer system is set up to communicate with another computer system, connectivity becomes the sixth system element. In other words, the manner in which the various individual systems are connected — for example, by phone lines,microwave transmission, or satellite — is an element of the total computer system.
Software consists of the programs that instruct the hardware to perform tasks. Without software instructions, the hardware doesn’t know what to do. People, however, are the most important component of the computer system: they create the computer software instructions and respond to the procedures that thoseinstructions present.
The basic job of the computer is the processing of information. Computers accept information in the form of instruction called a program and characters called data to perform mathematical and logical operations, and then give the results. The data is raw material while information is organized, processed, refined and useful for decision making. Computer is used to convert datainto information. Computer is also used to store information in the digital form.
There are two fundamentally different types of computers—analog and digital. (Hybrid computers combine elements of both types.) Analog computers solve problems by using continuously changing data (such as temperature, pressure, or voltage) rather than by manipulating discrete binary digits (1s and 0s) as digitalcomputers do. In current usage, the term computer usually refers to digital computers. Digital computers are generally more effective than analog computers for three principal reasons: they are not as susceptible to signal interference; they can convey data with more precision; and their coded binary data are easier to store and transfer than are analog signals. Such computers can represent anytype of data, from numbers to letters to musical notes. This process is called digitization.
Modern computers have a myriad of applications in fields ranging from the arts to the sciences and from personal finance to enhanced communications. The use of supercomputers has been well established in research and government.
A vague image of modern computer was first outlined in 1833 by Britishmathematician Charles Babbage1.
His design of an “analytical engine” contained all the necessary elements of a modern computer: input devices, a store (memory), a mill (computing unit), a control unit, and output devices. The design called for more than 50,000 moving parts in a steam-driven machine as large as a locomotive. Most of its actions were executed through the use of perforatedcards: a method that was already used to control automatic silk-weaving machines called Jacquard looms by the name of the inventor. It was one of the first programmable devices.
Herman Hollerith2, an American inventor, spent a calculating machine which was developed in the 1880s to count, collate, and sort information stored on punch cards. When cards were placed in his machine, they pressed on aseries of metal pins that corresponded to the network of potential perforations. His “tabulator” quickly demonstrated the efficiency of mechanical data manipulation. In 1896 Hollerith founded the Tabulating Machine Company to produce similar machines. In 1924, after a number of mergers, the company changed its name to International Business Machines Corporation (IBM)3. The most popular of...
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