Types of Computer

Computers can be used at school, hospitals, offices, resource, centers, musical composing companies etc.
Computers used in different sectors may not be the same type of computers. They may differ in processing, speed, storage capacity, size and nature of tasks which they can perform. The different types of as followings:
On the basis of Task- i) Analog ii) Digital iii) Hybrid

History of Computer

As the people learned how to count and calculate they started to search fast and accurate calculation device. The History of computers starts out about 2000 years ago at the birth of Abacus. Many mathematician and physicians had invented many other calculating machines. In 1937 AD Howard Aiken with IBM engineers had successfully developed the first automatic electromechanical computer,  MARK-I. The development of computers has passed many stages from the Abacus to modern computer. The development of computer:-
ABACUS- it is used for addition, subtraction, multiplication and division.
Napier’s Bone- Invented in 1614 by Scottish mathematician. This could perform multiplication and        Division of numbers.
Slide Rule (1620), Pascaline(1642),  Stepped Reckoner (1694AD), Jacquard’s Loom (1801AD), Different Engine (1822AD), Analyticv engine (1833AD), Tabulating Machine (1890AD), Harverd Mark-I (1937AD)
Atanosoft Berry Computer(1937-1942AD), ENIAC(1943 to 1946AD), EDVAC (1946-1952AD), EDSAC (1949 A.D.), Universal Automatic Computer (UNIVAC-I) 1951 AD- Computer for a commercial user)

Characteristic of Computer

A Computer possesses many wonderful characteristic. Due to its characteristic it is different from any other electronic devices. The computer has following major characteristic.

1. Speed
2. Accuracy
3. Diligence
4. Versatility
5. Storage
6. Automatic

Introduction

A Computer is a general purpose device that can be programmed to carry out a set of arithmetic or logical operations automatically. Since a sequence of operations can be readily changed, the computer can solve more than one kind of problem.
Conventionally, a computer consists of at least one processing element, typically a central processing unit (CPU), and some form of memory.  The processing element carries out arithmetic and logic operations, and a sequencing and control unit can change the order of operations in response to stored information. Peripheral devices allow information to be retrieved from an external source, and the result of operations saved and retrieved.
In  world war II, Mechanical analog computers were used for specialized military applications. During this time the first electronic digital computers were developed. Originally they were the size of a large room, consuming as much power as several hundred modern.