Definition of Computer :
§ The term computer is derived from the word ‘computer’, this means to calculate. But today’s computers are not just calculating devices..
§ Computers are versatile; they are capable of performing varied types of jobs and can handle multiple applications at one time.
§ The acronym for computer is:“Common Oriented Machine particularly used for Trade, Education and Research.”
§ A computer is an electronic device that manipulates information or data. It has the ability to store, retrieve, and process data and gives the output in a desired manner.
Characterstics of Computer:
§ SPEED: Computer is very fast calculating device. It can execute basic operations like addition, multiplication, subtraction and division at a few microseconds.
§ ACCURACY: The accuracy of Computer does not go down when they are used continuously for hours together. It always gives accurate results.
§ STORAGE: Computer has a very large storage capacity. It has an in-built memory where it can store a large amount of data. We can also store data in secondary storage devices like Floppy disk, Hard disk etc.
§ VERSATILITY: It means Computer can perform different types of job efficiently. Computer can work with different types of data and information such as visuals, text, graphics & video etc. at same time.
§ PAPER WORK REDUCED: The Computer reduces the paper work of any organization. The required data which was earlier stored in files, drawers and cabinets is now stored in the memory of computer. So Organisation can reduce the paper work.
§ MANPOWER REDUCED: The work which was done by many persons in an office can be done by one computer with more accuracy and efficiency. Thus an Organisation need less manpower or persons to employ.
§ DILLIGENCE: A Computer can work for long hours with the same accuracy and speed because it is free from the problems of boredom or lack of concentration.
Drawbacks of Computer :
Despite various advantages, computer have certain limitations also :-
§ NO IQ: A Computer is a dumb machine and it cannot do any work without instruction from the user. It has no intelligence of its own. So the Computer cannot take its own decision as we can.
§ NO FEELINGS: It does not have feelings or emotion, taste, knowledge and experience. That’s why it does not get tired even after long hours of work.
§ NO DECISION MAKING CAPABILITY: Computers are not capable of taking decisions. Human beings take decisions after analysis the output given by computer.
Applications of Computer :
The use of computer is well recognised, since we are living in the informative society.
Information Technology is playing an ever-growing role in our lives.
It includes telecommunications, microwaves, lasers and fibre optics along with computer.
There is no area of human life which is not affected by the power of computer systems.
Computer is a tool to work with information and to create new information. Following are the applications:-
§ Uses of Computers in Homes:These days, computers are essential for a family like washing machines and refrigerators. They are used for entertainment, watching movies, playing games etc. Computers are used to manage finanances, working in home away from office, Internet Backing, communication and information sharing, doing homework etc.
§ Computers in Education: More and more schools are adding computer technology to their syllabi so that students may be aware of the computer skills and may use these skills for other subjects also. Computers can be used for solving engineering, mathematical and scientific problems with great speed and accuracy. Students make use of Encyclopaedias to search and find useful information. They can read the books available online and can surf the e-libraries of other institutions.
§ Computers in Entertainment:Computer also finds place in music and entertainment industry. MIDI (Musical Instrument Digital Interface) is a tool for creating and recording music. Children particularly use of computers for the purposes of entertainment.
§ Computer and Health Care:Computers play a major rule in the field of medical diagnosis and health care. The detection of diseases and its suitable preparation has become fast and quick using IT tools. Moreover the diagnosis is accurate and quick. In health care, physicians and surgeons use computers for performing delicate operations, conduct surgeries, ultra sound and laser eye surgeries, MIR, CT scan and maintain patients record etc.
§ Computer and Weather forecasting: Computers are used to get correct and timely prediction of weather conditions. People working and living at sea shores and hilly areas make suitable arrangements for saving their lives and avoiding damages.
§ Computer and Business Sector:Computers also find place in business; even the small company’s use computers to perform their basic functions and to manage the accounting, inventory, marketing and payroll etc.
§ Computers in Banking: Banking functions in all the urban, semi-urban and rural areas are fully computerized. ATMs have been installed by all the banks at various locations to provide the facility of quick withdrawal of money at any time. Computerised statements of account and interest calculation can be obtained in few seconds, which was initially very time consuming job. the survival of banking industry is impossible without computers.
§ Computers in Communication:Now a day’s people don’t use convential methods of communication. They communicate through email, voice chat, audio and video conferencing. In these methods, We don’t have to arrange the meeting’s venues and management. Thus saves a lot of time and money. People communicate and exchange ideas sitting at remote graphical areas.
§ Computers and Industries:Industries use different types of computers in many combinations to automate their jobs. Computers are used to design and make new products, computer aided design(CAD) and computer aided manufacturing(CAM) of many parts.
§ Computers in Govt. Sector: Govt are also big consumers of technology. They use computers to calculate taxes and revenues, military people use computers for weapon control, to communicate on radio under water, on air and on the surface of the earth. Govt. also uses computerised control systems to manage traffic. Moreover airlines, railways are also computerised. the details of flights or rail can be easily found on the computers via Internet. The entire world has become small because of the availability of Information Technology.
§ Computers in Agriculture:Information Technology is used in crop farming and management practices. This area includes the control of pest and disease, weed control, land preparation and other related practices.
Components of Computer :
22. A computer system has mainly four basic units. These are:
§ Input Unit: This unit is used for entering data and programs into the computer system by the user for processing.
§ Storage Unit: The storage unit is used for storing data and instructions before and after processing.
§ Central Processing Unit: The CPU takes data and instructions from the storage unit and makes all sorts of calculations based on the instructions given to it. Then it is sent back to the storage unit. CPU includes Arithmetic logic unit (ALU) and control unit (CU).
§ Output Unit: The output unit is used for storing the result as output produced by the computer after processing.
History of Computers :
§ ABACUS was the first calculating device which was invented by Chinese. It consisted of a frame, which had number of wires and each wire contained some beads. The beads were used for counting and calculations. Here beads were stored at one side of the frame and moving the beads to another side performed calculations.
§ Napier’s Bones: Another accounting device invented by John Napier, a very strange Scotsman, “bones” were strips of ivory with numbers written in them. When the bones were arranged properly, the user could read the numbers in adjacent columns to get the answer of a multiplication operation.
§ The Pascaline-Adding Machine:Blaise Pascal invented the first machine which could add also called hand powered adding machines in early 1642. Machine invented by Blaise Pascal was so revolutionary that the principle behind it is still used in most of the mechanical computers being used today. Addition and subtraction could easily be performed; division could be performed by subtraction, multiplication and by repeated addition.