Brief Introduction of Computer- History, Features, Classification and Application of the Computer.

A computer is an electronic machine that accepts data from the user, process the data by performing calculation and operation on it and generates the desired output as a result. The term computer is derived from the latin word ‘computare’ which means ‘to computer’.

Generally, the computer is the combination of Hardware and Software which converts data into information. Computer operates on set of instructions only, they cannot think as a human being. Computer has an ability to store and execute a set of instructions called program which makes it extremely distinguishable and versatile than calculators. Computer makes people’s lives easier and more comfortable.

Table of Contents

Functioning of a Computer

Computer performs four functions which are as follows

Input:- Information or data that is entered into a computer is called input. It sends data and instructions to the Central Processing Unit (CPU).
Processing:- It is the sequence of actions taken on data to convert it into information which is meaningful to the user. It can calculations, comparisons or decisions taken by the computer.
Output:- It makes processed data available to the user. It is mainly used to display the desired result to the user as per input instructions.
Storage:- It stores data and programs permanently. It is used to store information during the time of program executions and possible to get any type of information from it.

Features of Computer

The key features of computer are as follows.

Speed:- The Computer can process data very fast at the rate of millions of instructions per second.
Accuracy:- Computers provide a high degree of accuracy. They respond to the user as per the input instructions.
Storage Capacity:- Computers are capable to store huge amount of data which depends on the capacity of the hard disk.
Versatility:- Computers can do different types of work simultaneously. They can perform multiple tasks at the same time.
Automatic:- Once the instruction to do any work is given to the computer, the computer does its work automatically by itself.
Diligence:- Unlike human beings, a computer is free from monotony, tiredness, lack of concentration, etc and can work for hours without creating any errors.
Secrecy:- Leakage of information is reduced by creating a login system with password protection.
Reliability:- Computer are more reliable than human beings. Computers always produces exact results. The possibility of errors occur only if the input is wrong, i.e. the computers never make mistakes of their own accord.
Plug and Play:-

History Of Computer

Computer is not the creation of one day, rather it took a long period for the development of modern computers. History of computer is described in this table.

Invention	Inventor	Characteristics	Applications
Abacus – 1602	China	First mechanical calculating device.A horizontal rod represents the one, tens, hundreds, etc.	Used for addition and subtraction operations.Calculation of square roots can also be performed.
Napier’s bones 1617	John Napier	Three dimensional structure.Holding numbers from 0 to 9 only.Represents graphical structure of calculating result.	Perform multiplication on numbers.Technology used for calculation called Robdologia.
Pascaline – 1642	Blaise Pascal	First Mechanical adding machine.It was structured like rectangular box, with eight disc (represent number of units).	Perform addition and subtraction of two numbers.Mainly designed with regard to the pressure of liquid.
Jacquard’s Loom 1801	Joseph Marie Jacquard	Mainly weaved a silk based pattern.Used punched card for the sequence of operation.	Simplified the process of Textiles.
Analytical Engine 1837	Charles Babbage (Father of computer)	First general-purpose computer.Stored program in the form of ‘pegs’ also called barrels.	It was a decimal machine used sign and magnitude for representation of a number.
Tabulation Machine 1880	Herman Hollerith	It used punched cards with round holes.It was the first electromechanical machine designed to process the data for census in 1890.	Read one card at a time.
Mark-1 1944	Howard Aiken	Consists of interlocking panels of small glass, counters, switches and control circuits.Data can be entered manually.	Mainly used in the war effort during world war-II.Magnetic drums are used for storage.
ENIAC 1946	JP Eckert and JW Mauchly	It is a combination of twenty accumulators.First electronic digital computer.	Used for weather prediction, atomic energy calculation and other scientific uses.
EDSAC 1949	John Von Morris Wilcus	It was the first computer which provide storage capacity.First computer program was run on machine.	Capable of storing instructions and data in memory.Used mercury delay lines for memory, vacuum tubes for logic.
UNIVAC 1951	Eckert John Mauchly	First general-purpose electronic computer with large amount of input and output.	Used magnetic tapes as input and output.
IBM-650 Computer 1954	IBM Company	Provide input/output units converting alphabetical and special characters to two-digit decimal code.	Payroll processing.Oil refinery design.Market research analysis.

Generation of Computer

A generation refers to the state of improvement in the development of system. Computers are built of electromagnetically, before generation. Each generation of computer is characterized by a major technological development that fundamentally changed the way computers operate.

Generation	Switching Device	Storage Device	Speed	Operating System	Language	Characteristics	Application
First (1940-56)	Vacuum Tubes	Magnetic drums	333 microsecond	Batch operating	Machine language	FastestHeatnot-portable	Used for scientific purpose
Second (1956-63)	Transistors	Magnetic core technology	10 microsecond	Time sharing system	Assembly language	More reliableHardware failureLess amount heat	Used for commercial purpose
Third (1964-71)	IC	Primary storage medium	100 nano second	Real time system	High level language	Consume less powerHigh sophisticated	Database m system
Fourth (1971-Pres.	LSI	Semiconductor memory	300 nano second	Time sharing gui interface	Pascal, ada, cobol	More reliableBetter communication	Distributed system
Fifth (Present)	SLSI	Optical disk	—–	Processing system		Parallel processingEnable mega chips.	Robotics

Classification of Computer

Computers are mainly classifieds as three types as follows.

Types of Computer -Based on Size

On the basis of size, computers are categorized as follows.

Microcomputer – Microcomputers are the least powerful, yet the most widely used and fastest growing type of computers and are also called portable computers. Microcomputer consists of three basic categories of physical equipment, i.e. system unit, input/output unit and memory unit.

Some types of microcomputer are as follows.

Desktop Computer or Personal Computer:- These are small, relatively inexpensive computers. There are based on the microprocessor technology (IC). In 1958, Jack Kilby and Robert Noyse invented the first IC.
Laptop:- These computers are also known as ultrabook or notebook. These are portable, lightweight and fit into most briefcases. They included rechargeable battery, so these can work anywhere.
Handheld Computer:- These are the smallest and are designed to fit the palm. So, these are also known as palmtop. They are practical for certain functions such as phone books and calendars. They use the pen for input instead of keyboard.
Tablet Computer:- They have key features of the notebook computer but these can accept input from a pen instead of a keyboard or mouse.
Personal Digital Assistant:- It is also known as a handled PC, or personal data assistant, is a mobile device that functions as a personal information manager.

Minicomputer – Minicomputer are smallest in size, fatest, cost lower than mainframe computers. Initially, the minicomputer was designed to carry out some specific tasks, like engineering and computer aided design calculations. But now, they are being used as central computer which is known as server. Minicomputer are IBM-17, DEC PDP-11, HP-9000, etc.

Mainframe Computer – Mainframe computers are those having large internal memory storage and comprehensive range of software. Mainframe computer serves as a backbone for the entire business world. It is considered as the heart of a network of computers or terminals that allows a large number of people to work at the same time. Mainframe computers are IBM-370, IBM-S/390, UNIVAC – 1110, etc.

Supercomputer – Supercomputers are the fastest and most expensive machines. They have high processing speed compared to other computers. The speed of supercomputers are measured in FLOPS(Floating Point Operations Per Second). Supercomputers are used for highly calculation intensive tasks, such as weather forecasting, nuclear research, military agencies and scientific research laboratories. Supercomputer are most powerful, large in size and memory, compared to all other computers.

Computer Types Based on Work

On the basis of work, computers are categories as follows.

Analog Computer – Analog computers are the job-oriented computers. They carry out arithmetic and logical operations by manipulating and processing of data. E.g. speedometers, seismographs, etc. Analog Computer can perform several mathematical operations simultaneously. It uses continuous variable for mathematical operations and utilize mechanical or electrical energy.

Digital Computer – Digital Computer work by calculating the binary digits. A digital computer, not only performs mathematical calculations, but also combines the bytes to produce desired graphis, sounds. E.g. desktop (PC).

Hybrid Computer – Hybrid computers are the combination of analog and digital computers. Machines used in hospitals like ECG and DIALYSIS are the commonly used hybrid computers.

Computer Types Based on Purpose

On the basis of purpose, computers are categorized as follows.

General Purpose Computer – General purpose computers are those computers, which are used to solve a variety of problems by changing the program or instructions. E.g. to make small database, calculation, accounting, etc.

Special Purpose Computer – special purpose computers are those computers which are used to solve a single and dedicated type of problems. E.g. automatic aircraft landing multimedia computer, etc.

Application Of computer

Now a days computers have been employed in almost all the aspects of professional and personal life. Some of the areas where computers are being used are as follows.

Education:- Computer have proved to be excellent teachers. Educational institutes are using computers in many ways like tele-education, virtual classroom, online classes, etc.
Science and Engineering:- Scientists have been long users of it. A new adventure among scientists is the idea of collaboratory, an internet based collaborative laboratory, in which researchers all over the world can work easily together even at a distance.
Industry:- Computers are used here to control manufacturing system and continuous running of the machinery. Parameters like temperature, pressure, volume are monitored and controlled by computers. Robotics developed with the help of computers play a very crucial role here.
Recreation:- Our entertainment and pleasure time have also been affected by computerisation.
Administration:- Various departments of the government use computer for their planning, control and law enforcement activities.
Health:- Computer plays a very crucial role in this area. Activities like scanning, X-ray, tele-medicine, patient monitoring, patient records, diagnosis, etc. are performed with the help of computers.
Multimedia:- It is the field concerned with the computer controlled integration of text, graphics, drawings, animation, audio and any other media where each type of information can be represented, stored transmitted and processed digitally.
Banks:- Computers can be used in the banks to keep the records of customer’s accounts.
Military Personnel:- They also make use of computers for their crucial tasks like determining the weather, computing the trajectories of missiles etc.
Business:- Using a wide range of business software a company’s marketing division can produce sales forecast and devise new strategies.
Commerce:- It is the activity of buying and selling of goods and services, especially on a large scale.
Publication:- Computers have made publication process an easy one. Without computers, the different parts of a publication-text, illustrations and graphics-must be created individually, then cut out and pasted down to form a page layout.