The word computer has come from the word compute that means calculating. Thus it is an electronic device which performs arithmetic operations such as addition, subtraction, multiplication and division at high-speed. The main objective of inventing computers is to process large arithmetic calculation. But nowadays, it is used to process non-arithmetical as well as arithmetical data. Hence defining computers as calculating device is to ignore their rest of the work. More accurately, it may also be defined as a man-made electronic machine which can operate on a large amount of data or information. Here data or information can be numerical or non-numerical and it can be of any size or shape. Non-numerical data can be a list of bio-data of many applicants when the computer is used for recruiting personal, or to prepare result of many students who have obtained marks in different subjects, or to store details of a person while booking ticket on airline or railways reservation. Computers can store, read and process data and produce a meaningful data as output. Computers work very fast and do not make mistakes. it can also be defined as it is a collection of hardware or software component to accomplish many tasks.
CHARACTERISTICS OF A COMPUTER
Today computes are the backbone of every business and leisure of life. The most common properties of computers which make them powerful machines are as listed below.
- ACCURACY AND RELIABILITY
- HIGH STORAGE CAPACITY
- POWER OF REMEMBERING
A computer is a very fast machine. It can do a job in few seconds or minutes for which a human being can take an entire year. The quick services we expect from bank, railway reservation, airline reservation, at the grocery store, at stoke exchange and while using Internet we are dependent on the speed of the computer. A powerful computer is capable of performing 3 to 4 million simple arithmetic per second. When we are taking about the speed of a computer, we do not talk in terms of second or millisecond. The unit of speed is microsecond or nanosecond or pico-seconds. The speed of a computer is measured in the following units of time:
Kilo instruction per second
Million instruction per second
ACCURACY AND RELIABILITY:
Accuracy of a computer is consistently high and the degree of accuracy of a particular computer is dependent on its hardware design. A particular computer has same degree of accuracy for each and every calculation performed in it. It does not create any error while calculation itself. The errors appeared in any calculation are caused by humans. It may be possible that the programmer has written wrong code for calculation based application or it may also be possible that the data which is provided to the computer is not right or insufficient. Reliability of a computer is extremely high. We can be completely dependent on a computer to get fine and accurate result if the user had provided the right and sufficient data.
A computer is free from monotony, physical and mental tiredness, and lack of concentration. Thus it can work for hours without stopping and can give accurate outputs. So that a computer scores over human being in doing routine type jobs that requires high accuracy. If a computer is ordered to process ten millions of calculation then it will calculate each with same speed and will provide output of each with same accuracy.
A computer has its wide use of field. It can be used in commerce, daily life for entertainment, scientific application as well as in education. As for example, one person who is creating a list of job applicants at one moment, at the next moment he can use the same computer for booking tickets or after some time he can watch movie or listen songs. So it is clear that a computer can be used for different purposes at different times.
HIGH STORAGE CAPACITY:
A computer is capable of storing huge amount of data. We can store data of any size in a computer at any time and we can also retrieve it any time very quickly.
When a process has been given to a computer and it is initiated then it does not need any person or help for functioning at each step of the process.
POWER OF REMEMBERING:
when a human being acquires new knowledge, the brain subconsciously selects what is important and retains it in its memory, and relegates unimportant details to the back of mind or just forgot them. With computers, this is not the case. It can store and recall any amount of information because of its secondary storage capability. Every piece of information can be retained by the user and can be recalled as and when required. Even after several years, the information recalled will be as accurate as on the day when it was fed to the computer. It forgets or looses 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.
LIMITATIONS OF COMPUTER
- NO I.Q.
- NO FEELING
- PRONE TO VIRUS
- DEPENDS ON ELECTRICITY
A computer has no I.Q. a computer can not perform tasks that a human can. The difference is that it performs these tasks with unthinkable speed and accuracy. It has no intelligence of its own. It has to be instructed to do and in what sequence. Hence only a user can decides what task a computer will perform. It has no brain or intelligence regarding this.
Computer have no feelings or emotions because they are machines. Based on our feelings, taste, knowledge, and experience, we make our decisions in our daily life but it can not do these thing. Their decisions are based on the instruction we give them in form of codes.
PRONE TO VIRUS:
A virus can affect the performance of a computer. Sometimes they can destroy our computers.
DEPEND ON ELECTRICITY:
Computers cannot be operated without electricity.
APPLICATION OF COMPUTER
Today computers are used in various fields and these are as follows:
Computers are used for playing games, listing music and watching movies. They are also used to create movies and to make drawings.
Today computers are used in school for teaching, doing mathematical calculations and making computer projects.
In banking sector computers are used to store information of its account holders, it is also used to keep record of cash deposit and withdrawal it is also used by the ATM.
RAILWAY STATIONS AND AIRPORTS:
At railway stations and airports computers are used to check seat availability and for seat booking. It is also used to see timings trains and airlines and to see the arrival and departure of trains and airlines.
In business, computers are used to prepare documents, letters and to print them. They also help to store records of all employees and other details of the business. It is also used to send E mails to business colleagues.
Now computers are used to design magazines, newspapers, books and advertisements, they are also used for design clothes, preparing blue prints of a buildings and for auto mobile designing.
Computers are used in administration at a large-scale for handling of all kind of works of administration.
Computers are used for desktop publication.
Different types of computers are used by the scientists for their different projects handling.
In Defence computers are used for designing weapons, controlling their functions and launching missiles and to store records of criminals. It is also used to connect soldiers with the operating base.
Computers are used in communication system.