Computer is made of a word “Compute” which means “to calculate”. Computer is not an acronym. In simple words- “Computer is an electronic machine which is used to do computation or calculation”.
According to Wikipedia definition
“A computer is a machine that can be instructed to carry out sequences of arithmetic or logical operations automatically via computer programming”.-Wikipedia
Some people define COMPUTER as:
U- Used for
E- Education and
But, according to me, it is not a right definition because first, computer is not an acronym which can be expanded and second when the computer were invented, they were just calculating machines which needs a lot of space for establishment.
What is computer?
A computer is just a general purpose electronic machine which is used to perform arithmetical and logical operations automatically.
A computer has an ability to follow a generalized set of operations called programs and acts accordingly. A computer is made mainly of two units:
- Arithmetic Logical Unit (ALU)
- Control Unit (CU)
Computer = Arithmetic Logical Unit (ALU) + Control Unit (CU)
What is Arithmetic Logical Unit (ALU)?
ALU stands for Arithmetic Logical Unit which is used to perform two classes of operations i.e. arithmetical and logical operations. The ALU supports addition, subtraction, multiplication, division, trigonometry functions such as sine, cosine, etc., and square roots also.
What is Control Unit (CU)?
The Control Unit (CU) is a component of a computer’s Central Processing Unit (CPU) which main act is to direct the operation of the processor. It tells the computer’s memory, arithmetic and logic unit and input and output devices how to respond to the instructions that have been sent to the processor.
History of Computers
First Computing Device
Before the invention of first computing device, the abacus was initially used for arithmetic tasks. It was the early of the 19th century when Charles Babbage, an English mechanical engineer and polymath, originated the concept of a programmable computer. He is considered as the father of Computer. He proposed the revolutionary difference engine which was designed to aid in navigational calculations. In 1833, he proposed a much more general design, an Analytical Engine. In these machines, the input of programs and data were provided via punched cards.
Types of Computers
Computers can be categorized of three types based on their characteristics:
1) Based on Technologies and Uses
- Analog computer
- Digital computer
- Hybrid computer
2) Based on Sizes
- Personal computer
- Mainframe computer
- Tablet computer
3) Based on Generation
- First generation computers: (1940-1956)- These computers were based on Vacuum tubes.
- Second generation computers: (1956-1963)- These computers were based on Transistors.
- Third generation computers: (1964-1971)- These computers were based on Integrated Circuits.
- Forth generation computers: (1971- Present)- These computers are based on Microprocessors.
- Fifth generation computers: (Present and Beyond)- These computers are based on Artificial Intelligence