## Introduction to Computer

Subject: Computer

#### Overview

Computers are the machines that can perform tasks or calculations according to set of instructions or programs. This note introduces you with the computer.
##### Introduction to Computer

Computers are the machines that can perform tasks or calculations according to set of instructions or programs. The term computer is derived from the word compute which means to calculate. Computer is an electronic device that can perform arithmetic and logical calculations faster. The first fully electronic computers, introduced in 1940s, were huge machines that required teams of people to operate. Compared to those early machines, today's computers are not only thousand times faster, they can fit on your desk, lap and even pocket. You must appreciate the impact of computer in our day-to-day life. The computer has been useful in reservation of tickets in Airlines and Railways, payment of telephone and electricity bills, deposits etc.

• Computers are very fast due to which thousands of job can be performed within a short period of time.
• Complex mathematical problems and logical operations can be solved by using this computer.
• As computer is a versatile device, multiple task like communication, graphics, documentation can be done.
• A huge amount of data can be stored and retrieved as it has high storage capacity.
• Computers are machine hence, they have no brain so they work according to the program instructions set inside it.
• It is an electronic device and it uses electrical sources to work, so it is very risky to store data and information on the computer independently because some electrical and electronic damages may damage the data. So we have to make regular backup of the data.
• Since computers are very expensive device, it becomes beyond the capacity of general user. But now a day its price is going down than past.
• Computers require dustless and temperature maintained environment for best performance.

##### Characteristics of computer
The characteristics of computer are explained below:
1. Speed: Speed of computer maybe defined as the time taken by a computer to perform a task. It takes only a few seconds for the calculations that we take hours to solve. It works in the fraction of second. Most of the computers work on Micro and Nano second. Its speed is measured in term of MHZ (Mega Hertz) and GMZ (Giga Hertz).
2. Accuracy: The computers are the accurate machine that can perform large number of tasks without errors, but if we feed wrong data to the computer it returns the same wrong information called GIGO (Garbage In Garbage Out). The degree of accuracy in a computer is very high and every calculation is performed with same accuracy. The accuracy level is determined on the basis of design of computer. The errors in the computer are due to human and inaccurate data.
3. Diligence: The capacity of computer of performing repetitive task without getting tired is called diligence. A computer is free from tiredness, lack of concentration, fatigue etc therefore it can work for hours without creating any errors. Even if millions of calculations are to be performed, computer will perform every calculation with same accuracy.
4. Versatility: The capacity of computer of performing more than one task at the same time is called versatility of computer. Versatility means the capacity to perform different types of work completely.
5. Storage: Computer has mass storage section where we can store large volume of date for future use. Such data are easily accessible when needed. Magnetic disk, magnetic tape and optical disk are used as mass storage devices. The storage capacity of computer is measured in terms of Kilobyte (KB), Megabyte (MB), Gigabyte (GB) and Terabyte (TB).
6. Automatic: Computer is an automatic machine which works without the intervention of the user. The user is required to give the data and utilize the result but the process is automatic.
7. Processing: Large volume of data can be processed in great speed. During processing there are different types of operation such as input and out operation, logical and comparison operation, text manipulation operation etc.
8. Non-intelligent: computer is a dumb machine which cannot do any work without the instruction of the user. The instructions are performed at tremendous speed and with accuracy. Computer cannot take its own decision and doesn't have feeling or emotion, taste, knowledge and experience etc.

##### Some useful technical terms
1. Raw facts or symbols used in computer. (Data)
2. Process of converting raw data into information. (Data processing)
3. Data and instructions given to the computer. (Input)
4. The major part of computer that performs the processing task. (CPU)
5. An error due to wrong input. (GIGO)
6. The result of data processing. (Information)
7. Main component used in second generation computer. (Transistor)
8. The repeatedly working capability of computer. (Diligence)
9. A collection of 4 bits. (Nibble)
10. The capability of computer that tells that it can be used in all fields. (Versatility)
11. The computers which are used for general purpose. (Personal Computer)
12. Process of removing errors in the program. (Debug)

##### Things to remember
• Computers are the machines that can perform tasks or calculations according to set of instructions or programs.
• Computers are very fast due to which thousands of job can be performed within a short period of time.
• Computers require dustless and temperature maintained environment for best performance.
• The characteristics of computer are speed, accuracy, diligence, automatic, processing and non intelligent.
• It includes every relationship which established among the people.
• There can be more than one community in a society. Community smaller than society.
• It is a network of social relationships which cannot see or touched.
• common interests and common objectives are not necessary for society.
##### Characteristics of Computers

Computer is an electronic data processing device capable of taking an input data, processing them and displaying the processed result at a very high speed under the control of set of instruction. The features of computer are:

• Speed
• Accuracy
• Versatility
• Diligence
Since, the computer accepts raw data as input and converts into information by means of data processing, it is called information processing machine (IPM).

Data is defined as the raw facts or symbols which are collected from various sources and need to be processed.Information is defined as the desired or meaning full result obtained after processing the data.

There common ability that every computer has are:

• To accept data and instructions.
• To process data.
• To give desired information.
The circuitries of computer are designed on the basis of electrical signals and data travel them as the speed of current, therefore the computer is able to perform any task at the high speed.
Computer always produce accurate result but sometimes the wrong result produced by the computer is the outcome of wrong instructions programs given by the user level which is termed as Garbage-In Garbage-Out (GIGO).
Computer is called diligent machine because it can perform the task repeatedly without loosing its speed and accuracy for a long time.
Computer is called versatile machine because it is used in almost all the fields for various purposes.
The capabilities of computer are:
i. Computer is a device capable of storing huge amount of data in small device.
ii. Computer is device capable of calculating very fast and accurately.
The limitations of computer are:
• Computer cannot change the processing steps itself.
• Computer cannot think since it does not have its own brain.
• Computer is faster to perform any task than any other devices ever invented.
• Computer is accurate and reliable than human being.
• Initially computer is expensive so each and every people cannot afford it.
• It is used for various computer crimes such as hacking, pornography etc.
Bug is an error or mistake due to the fault in computer hardware and program.
Debug is the process of removing bugs (errors) in the computer program.
The measuring unit of computer is as
 Unit Fractions of second Milliseconds(ms) One thousandth (1/1000) Micro seconds(Ms) One millionth (1/1000000) Pico seconds One billionth (1/1000000000) Nano seconds One trillionth (1/1000000000000)
computer is known as automatic machine because computer is diligence machine