What is Computer?

Computer stands for Common Operating Machine Particularly Used for Trade, Education, and Research. The word computer comes from the word compute which means to calculate. So a computer is normally considered to be a calculating device that can perform arithmetic operations at enormous speed.

In fact, the original objective for inventing the computer was to create a fast calculating machine. But more than 80% of the work done by computers today is of non-mathematical or non-numerical nature. Hence, to define a computer merely as calculating device is to ignore over 80% of its work.

More accurately, a computer may be defined as a device that operates upon data. Data can be anything like bio-data of various applicants when the computer is used for recruiting personnel, or the marks obtained by various students in various subjects when the computer is used to prepare results. Thus data comes in various shapes and sizes depending upon the type of computer application. A computer can store, process, and retrieve data as and when desired. The fact that computer process data is so fundamental that many people have started calling it a data processor.

The name data processor is more inclusive because modern computers not only compute in the usual sense but also performs other functions with the data that flow to and from them. For example, data processors may gather data from various incoming sources, merge (process of mixing or putting together) them all, sort (process of arranging in some sequence – ascending or descending) them in the desired order and finally print them in the desired format. None of these operations involve the arithmetic operations normally associated with the computing device but the term computer is often applied anyway.

The activity of processing data using a computer is called data processing. Data processing consists of three sub activities: capturing the input data, manipulating the data, and managing the output results. As used in data processing, information is data arranged in an order and form that is useful to the people who receive it. That is, information is relevant knowledge, produced as the output of data processing operation and acquired by people to enhance understanding and to achieve specific purposes. Thus data is the raw material used as input to data processing and information is the processed data obtained as the output of data processing.

FIGURE 1.2 Comparison of man and computer

We as human beings are same as computers because computer performs all things as human beings do, like as shown in above FIGURE 1.2 computer captures everything with the help of webcam and human beings captures everything through eyes, computer gives output through speakers and we, through mouth, power cell which is important for computer to live same as we need heart to live and many more.

Characteristics of Computer

The increasing popularity of computers has proved that is very powerful and useful tool. The power and usefulness of this popular tool are mainly due to its following characteristics:

Automatic

A machine is said to be automatic if it works by itself without human intervention. Computers are automatic machines because once started on a job, they carry on until the job is finished, normally without and human assistance. However, computers being machines, cannot start themselves. They cannot go out and find their own problems and solutions. They have to be instructed. That is, a computer works from a program coded instructions that specify exactly how a particular job is to be done. While the job is in progress, the program is stored in the computer, and the parts of the instructions are obeyed. As soon as one instruction is completed, the next is obeyed automatically. Some of the other characteristics of computers such as speed and accuracy are due to the fact that they are automatic and work on a problem without any human intervention.

Speed

A computer is a very fast device. It can perform in a few seconds the amount of work that a human being can do in an entire year – if he worked day and night and did nothing else. To put it in a different manner, a computer does in one minute what would take a man his entire lifetime.

While talking about the speed of a computer, we do not talk in terms of seconds or even milliseconds (10^-3). Our units of speed are the microseconds (10^-6), the nanoseconds (10^-9), and even picoseconds (10^-12). A powerful computer is capable of performing several billion (10⁹) simple arithmetic operations per second.

Accuracy

In addition to being very fast, computers are very accurate. The accuracy of a computer is consistently high and the degree of accuracy of a particular computer depends upon its design. But for a particular computer, each and every calculation is performed with the same accuracy.

The electronic circuits of a computer that perform computations have no mechanical parts to wear and malfunction, resulting in errorless operation continuously. Hence, if the input data entering the computer are correct and if the program of instructions is reliable, then we can expect that the computer generally will produce accurate output. Errors can occur in a computer, but these are mainly due to human rather than technological weakness, that is, due to imprecise thinking by the programmer (a person who writes instructions for a computer to solve a particular problem) or due to incorrect input data. Computers errors caused due to incorrect input data or unreliable programs are often referred to as garbage-in-garbage-out.

Diligence

Unlike human beings, a computer is free from monotony, tiredness, lack of concentration, etc., and hence can work for hours together without creating any error and without upset. Due to this property, computers obviously score over human beings in doing routine type of jobs, which require great accuracy. If ten million calculations have to be performed, a computer will perform the ten million calculations with exactly the same accuracy and speed as the first one.

Versatility

Versatility is one of the most wonderful things about the computer. One moment, it is preparing the results of particular examination, the next moment is the busy preparing electricity bills, and in between, it may be helping an office secretary to trace an important letter in seconds. All that is required to change its talent is to slip in a new program (a sequence of instructions for the computer) into it. Briefly, a computer is capable of performing almost any task provided that the task can be reduced to a series of logical steps.

Power of Remembering

As a human being acquires a new knowledge, the brain subconsciously selects what it feels to be important and worth retaining in its memory, and relegates unimportant details to the back of the mind or just forgets them. With computers, that is not the case. A computer can store and recall any amount of information because of its secondary storage capability. Every piece of information can be retained as long as desired by the user and can be recalled as and when required. Even after several years, the information recalled would be as accurate as on the day when it was fed to the computer. A computer forgets or loses certain information only when it is asked to do so. So it is entirely up to the user to make a computer retain or forget particular information.

No I.Q

A computer is not a magical device. It can only perform tasks that a human being can. The difference is that it performs these tasks with unthinkable speed and accuracy. It possesses no intelligence of its own. Its I.Q is zero, at least till today. It has to be told what to do and in what sequence. Hence, only the user can determine what tasks a computer will perform. A computer cannot take its own decision in this regard.

No Feelings

Computers are devoid of emotions. They have no feelings and no instincts because they are machines. Although men have succeeded in building a memory for the computer, but no computer possesses the equivalent of a human heart and soul. Based on our feelings, taste, knowledge, and experience, we often make certain judgements in our day-to-day life. But computers cannot make such judgements on their own. Their judgement is based on the instructions given to them in the form of programs that are written by us. They are only as good as man makes and uses them. 

Uses of Computer

FIGURE 1.3 Places where computers are used

·         Banks: All financial transactions are done by computer software. They provide security, speed and convenience.

·         Travel: One can book air tickets and make hotel reservations.

·         E-Learning: Instead of a book it is easier to learn from E-learning software.

·         Examinations: One can give online exams and also get their results.

 Made By: Chaudhary Amit V.