Computer:
  1.        The word computer comes from the word “compute”, which means, “to calculate”

  2.        Thereby, a computer is an electronic device that can perform arithmetic operations at high speed.

  3.        A computer is also called a data processor because it can store, process, and retrieve data whenev er desired.


                                DATA PROCESSING
The activity of processing data using a computer is called
data processing.
                                         Data
                                   Capture Data
                                Manipulate Data
                                 Output Results
                                    Information
Data is raw material used as input and information is
processed data obtained as output of data processing


                    CHARACTERISTICS Of COMPUTER
1) Automatic: Given a job, computer can work on it 
automatically without human interventions

2) Speed: Computer can perform data processing jobs 
very fast, usually measured in microseconds (10-6), 
nanoseconds (10-9), and picoseconds (10-12)

3) Accuracy: Accuracy of a computer is consistently high 
and the degree of its accuracy depends upon its design. 
Computer errors caused due to incorrect input data or 
unreliable programs are often referred to as Garbage-
In-Garbage-Out (GIGO)

4) Diligence: Computer is free from monotony, tiredness, 
and lack of concentration. It can continuously work for 
hours without creating any error and without grumbling

5) Versatility:Computer is capable of performing almost 
any task, if the task can be reduced to a finite series of 
logical steps

6) Power of Remembering: Computer can store and 
recall any amount of information because of its 
secondary storage capability. It forgets or looses certain 
information only when it is asked to do so

7) No I.Q.: A computer does only what it is programmed 
to do. It cannot take its own decision in this regard

8) No Feelings: Computers are devoid of emotions. Their 
judgement is based on the instructions given to them in 
the form of programs that are written by us (human 
beings



                            Evolution of Computers

§.     Blaise Pascal invented the first mechanical adding
machine in 1642.
§.     Baron Gottfried Wilhelm von Leibniz invented the first
calculator for multiplication in 1671.
§.     Keyboard machines originated in the United States
around 1880.
§.       Around 1880, Herman Hollerith came up with the concept of punched cards that were extensively used as input media until late 1970s.

§.    Charles Babbage is considered to be the father of
modern digital computers.
§.    He designed “Difference Engine” in 1822.
§.    He designed a fully automatic analytical engine in
1842 for performing basic arithmetic functions.
§.    His efforts established a number of principles that
are fundamental to the design of any digital
computer.
      
               Some Well Known Early Computer

§    The Mark I Computer (1937-44)
§    The Atanasoff-Berry Computer (1939-42)
§.   The ENIAC (1943-46)
§.   The EDVAC (1946-52)
§.   The EDSAC (1947-49)
§.   Manchester Mark I (1948)
§.   The UNIVAC I (1951)