电气工程及其自动化专业英语第五章课文翻译.docx

Most people can formulate a mental picture of a computer, but computers do so many things and come in such a variety of shapes and sizes that it might seem difficult to distill their common characteristics into an all—purpose definition. At its core, a computer is a device that accepts input， processes data， stores data, and produces output， all according to a series of stored instructions。 Computer input is whatever is put into a computer system. Input can be supplied by a person, by the environment, or by another computer。 Examples of the kinds of input that a computer can accept include the words and symbols in a document, numbers for a calculation， pictures， temperatures from a thermostat, audio signals from a microphone， and instructions from a computer program. An input device, such as a keyboard or mouse， gathers input and transforms it into a series of electronic signals for the computer。 In the context of computing， data refers to the symbols that represent facts, objects ， and ideas. Computers manipulate data in many ways, and we call this manipulation processing. The series of instructions that tell a computer how to carry out processing tasks is referred to as a computer program, or simply a program。 These programs form the software that sets up a computer to do a specific task。 In a computer, most processing takes place in a component called the central processing unit （CPU)， which is sometimes described as the”brain of the computer. A computer stores data so that it will be available for processing. Most computers have more than one location for storing data, depending on how the data is being used。 Memory is an area of a computer that temporarily holds data that is waiting to be processed, stored， or output。 Storage is the area where data can be left on a permanent basis when it is not immediately needed for processing。 Output is the results produced by a computer. Some examples of computer output include reports, documents， music， graphs, and picture