importance

The importance of the computer

Computers are tremendously important in a variety of ways. For example, they simplify many difficult or time-consuming tasks to an extraordinary degree. They provide businesses, governments, individuals, and institutions with an efficient way to manage large amounts of information. Computers also help people to understand things better by allowing them to make models and test theories.

The value of computers lies in their ability to perform certain basic tasks extremely quickly and accurately. These tasks include (1) solving numerical problems, (2) storing and retrieving information, and (3) creating and displaying documents and pictures.

Solving numerical problems. One of the most important and most difficult jobs performed by computers is the solution of complicated problems involving numbers. Computers can solve such problems amazingly quickly. In many cases, the solutions show how certain things work, behave, or happen.

In engineering and the sciences, the knowledge of how something works is often expressed in the form of an equation. An equation is a two-part mathematical sentence in which the parts are equal to each other. Engineers and scientists use equations or groups of equations to show how various things relate to one another. They use the solutions to these equations to predict what will happen if certain elements of a situation or an experiment are changed. Engineers and scientists rely on computers to solve the complicated sets of equations that they use to make predictions.

For example, with the help of a computer, an engineer can predict how well an aeroplane will fly. A large, complex set of equations expresses the relationships between the various parts of an aeroplane and what happens when the aeroplane flies. The engineer enters the numbers for the size and weight of a certain aeroplane's parts. The computer then solves the equations for this particular aeroplane. Based on the solutions, the engineer can predict how well the plane will fly. The engineer then might decide to change the size or weight of one of the aeroplane's parts to change the way it flies. Thus, the computer helps the engineer simulate (imitate) various conditions.

Computers help people develop and test scientific theories. A theory is a proposed explanation for how or why something happens. Theories, like known relationships, are often expressed as equations. Some equations are so complicated or time-consuming to solve that it would be impossible to develop the theory without the help of computers. Computers are particularly useful in developing and evaluating theories about things that are difficult to observe and measure.

For example, an astronomer can use the problem-solving ability of computers to develop theories about how galaxies are formed. First, the astronomer proposes a set of equations about a group of stars. A computer performs the calculations needed to solve the equations. The astronomer can then use the solutions to predict the shape of the galaxy that the stars should form if the theory is correct. To test the theory, the astronomer can observe a real galaxy to see if it has the predicted shape. If the galaxy's shape agrees with the theory, the astronomer becomes more convinced that the theory is correct. If the galaxy's shape does not agree with the theory, the theory is wrong. The equations must be changed, and new calculations must be performed.

In economics and finance, computers solve equations to make predictions about money. Many of the equations that economists and business people use to make long-range predictions are extremely complicated. But some of the most widely used of all computer programs rely on fairly simple equations. Such programs help people and businesses work out their taxes, create budgets, and calculate the value of their investments.

Storing and retrieving information. People use computers to store unbelievably large quantities of information. Information stored in a computer is sometimes called a database. Databases can be enormous--for example, a country's entire census might be contained in a single database. A computer can search a huge database quickly to find a specific piece of information. In addition, the information can be changed easily and quickly--often in less than a second.

The efficiency with which computers store and retrieve information makes them valuable in a wide range of professions. For example, scientists use computers to store and quickly find results of experiments. Libraries use computer catalogues to hold information about their collections. Hospitals use computers to maintain records about their patients. Governments store election returns and census information on computers.

All kinds of businesses rely on computers to store large quantities of information about their employees, customers, and products. Computers also allow markets for stocks, bonds, currency, and other investments to keep track of current prices around the world. Banks maintain many kinds of records on computers, such as account balances and credit card information. Anyone who uses an automatic teller machine (ATM) is using a computer terminal. When an identification card and number are entered, the ATM can provide account information, dispense cash, and transfer funds between accounts.

Creating and displaying documents and pictures. Computers can store a huge number of words in a way that makes it easy to manipulate them. For this reason, word processing is one of the most important and widespread uses of computers. A word-processing program allows people to type words into a computer to write articles, books, letters, reports, and other kinds of documents.

Word-processing programs make it easy for people to change text that has been typed into a computer. For example, they can quickly correct typing or spelling errors. Words, sentences, and entire sections of a document can be added, removed, or rearranged. If a computer is connected to a printer, the document may be printed onto paper at any time. Business people, journalists, lawyers, scientists, secretaries, and students are among those who benefit from word-processing programs.

Computers are also important in the publishing industry. For example, most books, magazines, and newspapers are typeset by computers. In addition, a process known as desktop publishing enables people to design and produce newsletters and other documents on personal computers. Documents that have been created in this manner look almost as if they have been professionally typeset.

Computer graphics--the use of computers to make pictures--make up one of the most fascinating and fastest-growing areas of computer use. Computers can produce pictures that look almost like photographs. First, the computer solves equations that predict how an object should look. It then uses these predictions to display a picture on a computer terminal screen or to print a picture on paper.

Computer programs that perform computer-aided design (CAD) are important in many fields, particularly engineering and architecture. CAD programs create pictures or diagrams of a new object. They then solve equations to predict how the object will work. Engineers and architects use CAD programs to design aeroplanes, bridges, buildings, cars, electronic machinery, and many other machines and structures.

Computers also can produce pictures by converting information into pictorial form. The pictures can serve a variety of purposes. For example, computers enable business people, economists, and scientists to plot graphs from lists of numbers.

In a technique called computerized tomography, or the CT scan, a computer uses X-ray data to construct an image of a body part on a screen. Doctors use these images to diagnose diseases and disorders (see COMPUTERIZED TOMOGRAPHY). Sophisticated radar systems use computers to produce detailed pictures, often for military use.

Computer graphics also are used to create electronic video games. Terminal monitors or TV screens can display game boards and moving pictures. The player may use a keyboard or some other device, such as a mouse or a joystick, to play computer games.

Computer designers are experimenting with using computer graphics to create virtual reality--an artificial world in which the computer user can seemingly move about and handle objects. One virtual reality system has a headset with two tiny display screens, one screen for each eye. Images on the screens produce a three-dimensional view. Sensing devices contained in a special glove tell the computer when the user moves the fingers or hand. The computer then changes the images to create the illusion of, for example, opening a door.

The images do not have nearly the detail of what is seen in the actual world. In addition, there is a delay between hand movements and the corresponding changes in the images. However, virtual reality has a variety of applications. These applications range from simple game sets to sophisticated equipment used to control robots.

Other uses. Many complex machines need frequent adjustments to work efficiently. Small computers can be installed inside these machines and programmed to make these adjustments. In modern cars, such embedded (enclosed) computers control certain aspects of operation, such as the mixture of fuel and air entering the engine. Today's commercial airliners and military planes carry computers that help control the aircraft. Embedded computers also control the movements of industrial robots and are used to guide modern weapons systems, such as missiles and field artillery, to their targets.

Computers can help solve many complicated problems that do not involve numerical equations. Doctors, for example, investigate illnesses, decide on diagnoses, and prescribe treatments. They solve such problems by applying their knowledge and experience, not by solving equations. A branch of computer science called artificial intelligence uses programs that help solve problems by applying human knowledge and experience. Artificial intelligence systems called expert systems enable computers programmed with vast amounts of data to "think" about numerous possibilities--such as diseases that certain symptoms could indicate--and make a decision or diagnosis.

Computers also can be used to communicate information over long distances. They can send information to each other over telephone lines. As a result, computers keep banks, newspapers, and other institutions supplied with up-to-the-minute information. A computer network consists of many computers in separate rooms, buildings, cities, or countries, all connected together. Computer networks allow people to communicate by using electronic mail--a document typed into one computer and "delivered" to another. Such documents generally travel in only a few minutes, even if they are being sent over a long distance.

Computers also are used in teaching. Programs that perform computer-aided instruction (CAI) are designed to help students at all levels, from elementary school to the university level. The student sits at a computer terminal. The terminal's screen displays a question for the student to answer. If the answer is wrong or incomplete, the computer may ask the student to try again. It then may supply the correct answer and an explanation. CAI is also used in some adult education programs and as part of the employee-training programs of some corporations.

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