Page 9 - DCAP101_BASIC_COMPUTER_SKILLS

Basic Computer Skills

Notes • Understanding of block diagram of computers
• Understanding of memory and its type

Introduction

The word “computer” comes from the word “compute”, which means, “to calculate”. Hence,
people usually use a computer to be a calculating device that can perform arithmetic
operations at high speed. In fact, the original objective for inventing a computer was to
create a fast calculating machine. However, more than 80% of work done by computers today
is of non-mathematical or non-numerical nature. Hence, to define computer merely as a
calculating device is to ignore over 80% of its functions.

More accurately, we can define a computer as a device that operates upon data. Data can be
anything like bio-data, hence computer is used for short listing candidates for recruiting;
marks obtained by students in when used for preparing results; details (name, age, sex, etc.)
of passengers when used for or railway reservations: or number of different parameters
when used for solving scientific problems, etc.

Hence, data comes in various shapes and sizes depending upon the type of computer
application. A computer can and retrieves data as and when desired. The fact that computers
process data is so fundamental that have started calling it a data processor.
The name data processor is more inclusive because modern computers not only compute in
the usual sense but also perform other functions with data that flows to and from them. For
example, data processors may gather data from various incoming sources, merge (process
of mixing or putting together) them all, sort (process of arranging in some of sequence—
ascending or descending) them in the desired order, and finally print them in desired format.

Notice that none of these operations involves arithmetic computations in the usual sense but
a computer is the most suitable device for performing them.

People usually consider a computer to be a calculating device that can
perform arithmetic operations at high speed. It is also known as a data
processor because it not only computes in the usual sense but also
performs other functions with the data.

The activity of processing data using a computer is called data processing. Data processing
consists of three sub-activities: capturing input data, manipulating the data, and managing
output results. As used in data processing, information is data arranged in an order and form
that is useful to people receiving it. Hence, data is raw material used as input to data
processing and information is processed data obtained as output of data processing.

1.1 Characteristics of Computers

Increasing popularity of computers has proved that it is a very powerful and useful tool.
The power and useful of this popular tool are mainly due to its following characteristics:
1. Automatic. An automatic machine works by itself without human intervention.
Computers automatic machines because once started on a job, they carry out the job
(normally without a human assistance) until it is finished. However, computers being
machines cannot start themselves and cannot go out and find their own problems and
solutions. We need to instruct a computer using coded instructions that specify exactly
how it will do a particular job. Some of the other characteristics of computers (such
as speed and accuracy) are because they are automatic and work on a problem without
any human intervention.

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