what is computer ? Neb Class 12 computer Science

INTRODUCTION

- The term computer originates from the word 'computare, (which means to calculate). Humans are always involved in some kind of calculations-simple or complex. Mathematical addition, subtraction, multiplication, division, etc can be solved easily with simple tools, mouth and fing or sometimes we may need formulas, pen and paper, or calculating machines. Such calculations can be simple, consuming less time, while some can be complex and so difficult that the simple tools, formulas or methods may not work. Even the calculation may take a long time, and the ch can be wrong or inaccurate. Therefore, the man was always in search of a machine that could perfect alt kinds of calculations faster and accurately. This gave birth to a machine which is commonly known as 'computer".

Reservation of tickets in Air Lines and Railways, payment of telephone and electricity bills, deposits and withdrawals of money from hanks, business data processing medical diagnosis, weather forecasting, etc. are some areas where computers has become very useful.The number of applications of a computer, the speed and accuracy of calculation has increased. 

However, there is one limitation of the computer. Human beings do calculations on their own. Bod computer is a dumb machine and it has to be given proper instructions to carry out its calculation. Th why we should know how a computer works.Some countries are called developed, some developing and others underdeveloped. In the past, mamy countries which were able to catch up the opportunities brought about by industrial revolution became industrialized. Now we are in the process of another industrial revolution. This second industria revolution is the result of invention of computer technology. It is one of the greatest inventioris of human mind. Computer technology has been playing important role in every sector of our daily life. Compute has strengthened our capacity in numerical computations, information processing, storage, modeling and Simulation, concepts of globalization, increasing working capability and efficiency, converting onli approach, decreasing physical present etc.

It basically performs the following three functions in sequence;

• Receive raw data and instructions from input devices

• Process data according to the instruction, and

• Produce useful output and stored information for future used.

Computer has become an indispensable machine to increase the effectiveness and efficiency of everyperson, organization, country, students, teachers, scientist, researchers, and of every field including education, business and industry, science, technology, astrology, mining, astronomy, and many more. The computer can be better understood if we know the technology used in computer, and characteristics and application of computers. 

CHARACTERISTICS OF COMPUTER

Now-a-days computer is playing an important role in every sector of daily life; it has become a basic need of most of the people just like television, telephone or other electronic devices at home, and gaining popularity among others as well. It can solve numerical, logical or other decision related human problems very quickly as well as accurately. The important characteristics of a computer are described below

1. Speed: The computer is a very high-speed electronic device. The operations on the data inside the computer are performed through electronic circuits according to the given instructions. The data and instructions flow along these circuits at high speed that is close to the speed of light. Computer can perform millions of billion of operations on the data within a second. The computer generates signals during the operation process therefore the speed of computer is usually measured in megabertz (MHz) or gigahertz (GHz). It means million cycles units of frequency is hertz per second. Different computers have different speeds.

2. Accuracy:Besideso being very fast, the computer is a very accurate device. It gives precise output result provided that the correct input data and set of instructions are given to the computer. It means that output is totally dependent on the given instructions and input data. If input data is in-correct then the resulting output will be in-correct. In computer terminology, it is known as garbage-in garbage-out.

3. Reliability: The electronic components in modern computers have a very low failure rate. The modern computer can perform very complicated calculations without creating any problems and produces consistent (reliable) results. In general, computers are very reliable. Many personal computers have never needed a service call. Communications are also very reliable and generally available whenever needed.

4. Storage: A computer has internal storage (memory) as well as external or secondary storage. In secondary storage, a large amount of data and programs (set of instructions) can be stored for future use. The stored data and programs are available any time for processing. Similarly information downloaded from the internet can be saved on the storage media.

5.Retrieving data and programs: The data and program dored on the storage media can be retrieved very quickly for further processing or use. It is abo very important feature of a computer

6.Automation: A computer can automatically perform operations withest interfering to or the intervention of the user during the operation..

7. Versatility: Venatile means flexible. Modern computer can perform different kind of tasks one by one or simultaneously. It is the most important feature of computer. At one moment you are playing game on computer, the next moment you are composing, and sending emails etc. In colleges and universities computers are use to deliver lectures to the students. The talent of computer dependent on the software. Computer can be used in every field like science and technology, automation, education, medicine, e-governance etc

8. Communications Today computer is mostly used to exchange messages or data through computernetworks all over the world. For example the information can be received or send through the internet with the help of computer. Similarly, telecommunication networks are controlled and switched by computers. It is most important feature of the modern information technology

Note : Computer is an electronic machine that can perform varieties of task according to the input given by the user. Its normally works on the process of input process and output