What is a Computer| From gettecnoguide

Basic Of Computer Knowledge 

In this blog, we can learn the basic knowledge of computers for beginners.

First of all the first question arises in our mind that What is a Computer with a definition:

A computer is an electronic machine that can perform a variety of tasks such as mathematical and logical calculation, writing letters, drawing pictures, listening to music, watching movies, playing games, sending and getting information on the Internet, keeping records, doing calculations, controlling the robot, launching rockets and so on.

The computer can perform a variety of tasks according to a set of instructions given to it at high speed. The computer can quickly store, retrieve, and process the data. 

The set of instructions given to the computer in a programming language is known as a computer program. A computer processes the data according to the program instructions and produces meaningful information called result or output. 

The set of programs that instructs the computer to perform certain tasks is called software.

Next, What is the definition of a computer:

The word computer derived from the word computare which means to calculate. In the past, the computer was normally considered as a calculating device used to perform different mathematical and logical calculations. But today's modern computer is able to perform several tasks. So, a computer can be defined as:

A computer is an electronics machine, which generates information by processing raw data according to the prescribed sequence of instructions. It can also store the data and information for future use.

A computer is an electronic machine, that accepts the data and instructions from the user, processes the data according to the given set of instructions, stores, and gives the information (result).

Working of a computer:

Here we can learn how does computer work step by step:

A computer is an electronic machine that converts data into information by performing various actions on the data. A computer accepts data through input devices processes them according to the given set of instructions. 

Such instructions are stores in the form of a computer program. Converting pieces of data into useful information is a key task of the computer. 

For example, a computer might perform a mathematical operation on two numbers or logical operations such as comparing two numbers and then display the result. Such an operation performed by the computer is called the working principle of a computer.

The working principle of a computer has four steps. They are as follows:

Input: In these steps, the computer takes data from the user through input devices such as the keyboard, mouse, joystick, scanner, microphone, etc.

Processes: During this step, the computer's processing devices(CPU) processes the input data based on instructions from the users of a program. CPU is the main processing unit of a computer.

Output: In this step, the computer displays the result of its processing. After processing input data, the computer gives meaningful information called Result or Output. 

The output may appear as text, numbers, or graphics on the monitor or as sounds from its speaker. 

The computer can send the output to the printer to give hard copy output on the paper.

The computer also can send the output to another computer through a network or internet. 

The common output devices of the computer are a monitor, printer, plotter, speaker, etc.

Storage: In the last step, the computer permanently stores the result of processing or output on a hard disk, CD/DVD, or some other kind of storage medium.

Working of a computer

The Characteristics and Limitations of a Computer:

The computer is being the most useful machine in today's world. It is playing the main role in everyday life. It can perform the task very quickly as well as accurately. A computer has many special features that make it such a useful machine. 

So Next, What are the characteristics or features of a computer:

High Speed: A computer is an electronic device that transfers data at high speed through electronic circuits. The electronics circuit is designed in such a way that the electrical signal travels at the speed of light. So, the computer can process millions of data within a fraction of a second. 

The time is taken by a computer to perform an operation is called the processing speed. This processing speed of a computer is measured in terms of MegaHertz(MHz) GigaHertz(GHz) that is the speed of the CPU. 

Two important factors that determine the speed of a computer are the amount of data that the CPU can process in a given period of time and the CPU's clock speed. The speed at which a CPU executes instructions is called the clock rate.

The faster the clock, the more instructions the CPU can execute per second. Clock speeds are expressed in MegaHertz(MHz) or GigaHertz(GHz). 

Mega means million and hertz means times per second, 100 MHz is 100 million times per second and 100 GHz is 100 billion times per second. The time taken to perform a task by a computer is measured in a fraction of seconds.

Accuracy: A computer is not only fast, but it is also a very accurate machine. Huge databases are dealt with in a much more reliable manner by a computer but it is very difficult to deal with people. 

If the input data and instruction given to the computer are correct, it always gives the correct result or output. It means that the result is totally dependent on the given instructions and input data to the computer. 

If input data is incorrect then the output will be incorrect. In computer terminology, it is called garbage-in-garbage-out (GIGO).

Diligent: A computer is a diligent machine. Diligent means are hard work. A computer never gets tired while working. 

A computer can work for a long time without taking a rest. It can continually work for a long time without creating any error. 

It performs the operations with the same accuracy as well as the first one.

Consistency: A computer can repeat the same task consistently (again and again) without feeling boring. 

A computer will perform a task, in the same way, every time. 

You can listen to music, draw pictures, or perform any task repeatedly on the computer.

Versatile: A computer is a versatile machine. Versatile means are flexible, multitalented, or all-around. It is the most important feature of computers. 

The computers are able to run a number of different programs efficiently and without slowing down. A computer can perform different kinds of tasks one by one simultaneously. 

It can perform several tasks such as calculations, drawing pictures, playing games, playing music, writing letters, sending e-mails, etc.

High Storage Capacity: All computers have a memory that is used to store vital information necessary for running programs and retrieving information. 

There are two types of storage devices in the computer: internal storage or main memory and external storage or secondary storage. 

Secondary storage is used to store a large amount of data and programs for future use. The stored data and programs are available at any time for future use. 

The internal storage devices of computers are RAM and ROM and external storage devices of computers are Hard disk, CD-ROM, DVD, pen-drive, etc. 

Automation: A computer does not interfere with the user during the processing of data. It can automatically perform operations. 

It executes automatically the program instructions one by one. It controls automatically different devices attached to it. 

To make the computer work automatic, a set of pre-defined instructions are fed into the computer. The set of predefined instructions is called a program or software.

Communications: Nowadays computers are being the most widely used means of communication. It is the most important feature of modern information technology.

The computer is used to exchange messages or data through the Internet all over the world. With the help of the computer, we can quickly receive or send information throughout the world.

Limitations or Disadvantages of Computer:

A computer is a man-made machine and it only does things that the human programs it to do. However, the computer is programmed to work efficiently, fast, and accurately but it is programmed by human beings to do so. 

Without a program, a computer is nothing. A computer does not have common sense. Some of the limitations or disadvantages of computer are given below:

No Self-Intelligence: A computer can do very complex and dangerous tasks that are impossible for a human being. But the Computer does have any self intelligence. It only does the things that human programs it to do. It just follows our instructions.

No Thinking and Decision-Making power(NO IQ): The computer cannot think of itself. The concept of artificial intelligence shows that the computer can think. 

But still, this concept is dependent on the set of instructions provided by human beings. It cannot take any decision of its own.

It does only those tasks, which are already instructed to it in the form of a program. It is we to decide what we want to do and in what sequence.

No Feeling: A computer does not have feelings or emotions like humans. It does not distinguish between users. It can do very risky and dangerous work which is impossible for human beings.

No Learning Power: The computer has no learning power. Once we give instructions to a computer on how to perform a task, it cannot perform the same task if we do not give it any instructions for the next time.

 A History of Computer:

The origin of the computer starts with counting. Having the right tool to perform the right calculation has always been important for human beings. 

Many years ago, people used their fingers and pebbles for counting. The fingers and pebbles were used in the performance of simple calculations such as addition, subtraction, etc. 

This method of counting devices. In order to simplify the process of counting, people built a counting device called ABACUS. 

As time passed, many computing devices such as Napier's bone, slide rule, etc. were invented. In 1642, a French mathematician, Blaise Pascal invented the first functional automatic calculator to do calculations along with growth in human activities. 

Hundreds of scientists have been involved in the development process of computers. This tireless effort of scientists, mathematicians, philosophers, engineers, professors, etc. who were directly or indirectly involved in the development of various computing devices, helped to bring modern computers to this stage. 

A short introduction to computer history is described below:

Abacus: The Abacus is known to be the first calculating machine that was invented by a Chinese mathematician around 300B.C. 

An Abacus consists of a rectangular wooden frame structure with a series of vertical rods on which numbers of wooden beads are allowed to slide freely. 

The frame is divided into two parts and a bean separates these parts. The upper part is called heaven and the lower part is called earth. 

In the heaven part, each wire/rod has two beads whereas, in the earth part, each wire/rod has five beads. Calculations are performed by manipulating the beads up or done with fingers.

Napier's Bone: This was invented by a Scottish mathematician and scientist John Napier in 1614. It used rods that were similar to human bones. This gave the rise to the name Napier's Bones.

It could multiplication and division of large numbers with the help of rods. The rods consist of strips of wood, metal, or heavy cardboard. 

These are ten rods corresponding to the digits 0-9, and a special eleventh rod that is used to represent the multiplier.

Slide Rule: Slide Rule was invented by William Oughtred in 1920. He made the first slide rule by inscribing logarithms on wood. 

The slide rule is used primarily for multiplication and division and also for functions such as roots, logarithms, and trigonometry.

Before the invention of the pocket or handheld calculator, the slide rule became a very popular calculating device. 

A simple Slide Rule consists of two movable marked scales in which one scale slips upon the other.

Slide Rule (commons.wikimedia.org)

Adding Machine or Pascaline: This was invented by French mathematician Blaise Pascal in 1942. It was the first functional automatic calculator that could add and subtract directly.

Multiplication and division could be performed by repeated addition and repeated subtraction respectively. It contains dials, gears, and wheels.

Adding Machine or Pascaline (commons.wikimedia.org)

Stepped Reckoner: The German mathematician Gottfried Wilhelm Von Leibniz was invented a digital mechanical calculator called Stepped Reckoner in 1671.

He developed this machine by using Blaise Pascal's idea. Stepped Reckoner was the first calculator that could perform- addition, subtraction, multiplication, and division. 

Even square roots could be calculated by a series of stepped additions.

Stepped Reckoner (commons.wikimedia.org)

Jacquard's Loom: In 1801, a French silk weaver Joseph Marie Jacquard invented the automatic weaving machine called Jacquard's Loom. 

The function of that loom depended upon the absence or presence of holes on the punched cards. This concept gave the idea of a binary digit (0,1).

It could be considered the idea of a first programmable device.

Jacquard's Loom (commons.wikimedia.org)

Difference Engine: The real beginning and the actual thought of the modern computer was made by an English mathematician Charles Babbage. 

He originated the concept of a programmable computer machine called Difference Engine in 1822. However, Babbage never quite made a fully functional Difference Engine due to the lack of resources. 

This machine was capable to store programs, perform calculations, and print the result automatically.

Difference Engine (commons.wikimedia.org)

Analytical Engine: Charles Babbage, an English mathematician developed this machine in 1983, this machine could perform a lot of calculations. The machine had the following features:-

• Punch card system as an input device
• External memory
• Power to do arithmetical calculations
• With a speed on addition in one second

These features are fundamental in nature and are a true sense that had a great pioneering work in the field of development of computers. For this reason, Charles Babbage is called the Father of modern computers.

Analytical Engine (commons.wikimedia.org)

Lady Augusta Ada Lovelace: Lady Augusta Ada Lovelace, was an English writer as well daughter of famous English poet Lord Byron. 

She suggested Charles Babbage use a binary number system for programs and data to be fed into the Analytical Engine. So, she is regarded as the world's first computer programmer. 

She made some programs for Charles Babbage's Analytical Engine. In 1979, the US Department of Defense developed a programming language and named "ADA" in her honor.

Lady Augusta Ada Lovelace (commons.wikimedia.org)

Herman Hollerith and his Tabulating Machine: Dr. Herman Hollerith, an American census statistician, developed Tabulating Machine in 1887. 

The tabulating machine was developed to help process data for the 1890 U.S. Census. Herman Hollerith established the tabulating machine company in 1886. 

This company later in 1924 merged with other companies and formed the International Business Machine (IBM) Corporation. It is today's one of the leading computer manufacturing companies in the world.

Tabulating Machine (commons.wikimedia.org)

Mark - I: The professor of Harvard University, Howard Aiken, developed an Electro-Mechanical Computer called Mark-I in 1937. 

In earlier days it was called the Automatic Sequence Controlled Calculator(ASCC) and later renamed Harvard mark-I. It was built as a partnership between Harvard and IBM. 

The machine had a 50 ft rotating shaft running its length, turned by a 5 horsepower electric motor, weighted 5 tones, incorporated 500 miles of wires. It uses 1800 vacuum tubes to store data in the memory.

Mark - I (commons.wikimedia.org)

Atanasoff Berry Computer (ABC): Atanasoff Berry Computer (ABC) was the first electronic digital computer. 

This computer was designed by Dr. John Vincent Atanasoff and Clifford Berry in 1942. It used 19000 vacuum tubes as the main memory to store data. 

ABC was mainly used by the military to compute firing and blasting data.

Atanasoff Berry Computer (ABC) (commons.wikimedia.org)

ENIAC: Electronic Numerical Integrator and Calculator (ENIAC) was the first general-purpose electronic computer. 

It was built in 1946 at the University of Pennsylvania, the USA by John Mauchly and J.Presper Eckert. It was a digital computer capable of being reprogrammed to solve a full range of computing problems. 

It had almost 17,468 vacuum tubes, 7,200 crystal diodes, 70,000 resistors, 10,000 capacitors, and around 5 million hand-soldered joints. 

It weighed more than 30 tons, was roughly 8 by 3 by 100 feet, took up 1800 square feet, and consumed 150 KW of power.

ENIAC (commons.wikimedia.org)

EDSAC: An early British Computer was the Electronic Delay Storage Automatic Calculator (EDSAC). It was developed by Maurice V. Wilkes and his team at the University of Cambridge in England in 1949. 

It is the first computer used to store a program. It used 3,000 vacuum tubes to process data. In the EDSAC, programs were input using paper tape and output results were passed to a teleprinter.

EDSAC (commons.wikimedia.org)

UNIVAC-I: The Universal Automatic Computer-I (UNIVAC-I) was the first commercial computer produced in the United States. 

It was designed principally by the ENIAC in 1951. The UNIVAC was the first computer that uses buffer memory. It used 5,200 vacuum tubes to process data. 

The machine was 25 feet by 50 feet in length, contained 5.600 vacuum tubes, 18,000 crystal diodes, and 300 relays. It had an internal storage capacity that was capable of stores 1,000 words or 12,000 characters. 

Power consumption was about 120kva. The UNIVAC was also the first computer to come equipped with a magnetic tape unit.

UNIVAC-I (commons.wikimedia.org)

EDVAC: The earliest electronic computer was the Electronic Discrete Variable Automatic Computer(EDVAC). It was the first stored-program computer. 

The University of Pennsylvania's Moore School of Electrical Engineering was built the EDVAC for the U.S.Army's Ballistics Research Laboratory. 

This computer was developed by J. Presper Eckert and John William Mauchly using the concepts of Hungarian mathematician, John Von Newmann in 1952. It covered 490 ft square of floor space and weighed 17,300 lbs(7,850 kg). 

It consumed 56 Kilowatt of power and 12,000 diodes and had almost 6,000 vacuum tubes.

A History Of Computer (www.visme.co)

Types of Computer:

What are the 7 types of computer: They are: 

1. Analog Computer 
2. Digital Computer
3. Hybrid Computer
4. Micro Computer
5. Mini Computer 
6. Mainframe Computer 
7. Super Computer.

1. Analog Computer: It takes input in the form of an electrical pulse. The input is like age, pressure, current, water flow, etc. 

The process of feeding data is an Analog computer that is predefined and operation with the data and the output follows a standard set of guidelines. Outputs are generally a graph or picture or a table and give a signal for control of the operation. 

Analog computer works in the industrial field in controlling various physical parameters or stimulating them to find the optimum solution. Analog computer example, a speedometer is an Analog device, which shows only the speed of vehicles. 

Analog computer Examples are Analog watch, voltmeter, the Analog computer used to measure a gas line's meter in a petrol pump, seismograph, etc. These devices have low storage and less memory capacity.

2. Digital Computer: It operates directly on data which is represented in decimal digit form. This data may be number or characters which are fed through input devices like the punched card, keyboard, or magnetic media. 

Digital computers have the ability to handle large volumes of data by way of storing them in the machine in the Binary form i.e. 0 or 1, process them, and generating reports. 

Digital computers are used in commercial data processing or work like research mainly in the form of mathematical operations. Example- Any business computer.

3. Hybrid Computer: It process both continuous and discrete data. The hybrid computers can perform the tasks done by Analog as well as digital computers. For example, computers used in hospitals, jet planes, scientific labs, large industries, etc.

4. Micro Computer: The microcomputers are also known as personal computers or simply PCs. It used microprocessors as their CPU. 

The first microcomputer was designed by IBM in 1981. Microcomputers are very easy to use and used by one person at a time. So, microcomputers are also known as single-user computers. 

The most popular types of personal computers are PC and Apple.

5. Mini Computer: Minicomputers are more powerful than microcomputers. They are larger in size, have higher processing speed, and also have a higher cost than microcomputers. 

These computers are commonly used as servers in-network and hundreds of personal computers can be connected. The first minicomputers were introduced in the mid-1960s by Digital Equipment Corporation(DEC). 

6. Mainframe Computer: Mainframe computers are more powerful than minicomputers. They are larger in size, have higher processing speed larger storage capacity, and expensive than minicomputers. 

These computers require a large room with an air conditioner. They have multiple precessors. Thousands of users can use one computer at a time.

For example, the IBM SI390 mainframe computer can support 50,000 users simultaneously. The mainframe computers are specially used as servers in large organizations such as Banks, Airlines, and Universities, etc., where many users need frequent access to the same data. 

IBM is the major manufacturer of mainframe computers. The examples of mainframe computers are IBM S/3909, Control Data Cyber (CDC) 6600, etc.

7. Super Computer: They are the most powerful computers in the world. They are larger in size, have the highest processing speed, and the most expensive than other computers. 

Supercomputers were developed in the 1980s. They are used to process large amounts of data and to solve complicated scientific problems. Super Computer can perform more than one trillion calculations per second. 

It has a large number of processors connected parallelly. So, parallel processing is done on this computer. Thousands of users can work at the same time in a single supercomputer. 

They are mainly used for Weather forecasting, online banking, Nuclear energy research, Aircraft design, etc. For example, CRAY-1, CRAY-2, Control Data CYBER 205, ETA-10, etc.