Define computer and history of computer

 Introduction To Computer

The word computer is derived from Greek word “Compute” that means to calculate.
Computer is an electronic device which can accept the input data, process  the data, and give the result of the process data according to instruction.
OR
Computer is an electronic machine used to solve different problems according to set of instructions given to it.
A computer can accept data, process data into useful information and store it for later use.

History of computer

Computer was invented because “necessity is the mother of invention”.
The history of computer is very old. It goes back to some 500 year BC. 
The first computing machine was used by the Chinese before 15th Century his name Tim Cranmer . The name of this machine was Abacus.

Abacus

Abacus was first computing device. It was developed 5000 year ago.
it was used to perform simple addition and subtraction. 
Abacus was a wooden rack . It contained horizontal wires with beads stung on them. The beads could move easily.
All simple arithmetic calculations were performed by moving these beads according to programing rules.

Abacus 

Pascaline Calculator

After abacus a French mathematician Blaise Pascal invented a mechanical adding machine in 1642.
After Pascal a German scientist Von Leibnitz developed a calculating machine in 1694.  it was the first calculator that multiply and divide also. It was similar to Pascal but it was more reliable and accurate.

Pascaline Calculator 

Difference Engine

In 1822, an English mathematician from Cambridge university Charles Babbage invented a DIFFERENCE ENGINE for mathematical calculations also for capable of calculating powers of numbers.
Charles Babbage also gave the idea of ANALYTICAL ENGINE which was supported to be general purpose machine having the ability to calculate various arithmetic and algebraic formulas, store data and print results. 
Unfortunately he died soon and never converted his dreams into reality.
Charles Babbage is the father of computer.

Difference Engine 

Mark 1 (1937-44) 

It is also known as Automatic Sequence Controlled Calculator. It was first fully automatic calculating machine. It was designed by Howard A. Aiken of Harvard University. It was very reliable but huge in size.

MARK I 

ENIAC (1943-46)

In 1946 jhon mauchly and Jhon Presper Eckert develop an electronic Numerical integrator and computer ( ENIAC)  
It was the first electronic computer. It was very heavy and large in size. It consumes 140 kw of power. It could perform 5000 addition per second.

ENIAC

EDVAC (1946-52)

EDVAC Stand for Electronic Discrete Variable Automatic Calculator. 
It was developed by Dr, john Von Neumann with a memory to hold both a stored program as well as data.

EDVAC 

UNIVAC (1952)

UNIVAC stand for Universal Automatic Computer.
Eckert and Mauchly formed Eckert-Mauchly Computer in 1947 to manufacture computers commercially.
They manufactured the first successful computer UNIVAC. It was the first computer for commercial use.

Univac