The definition of a computer
The Computer is an electronic
device that converts unorganized data into meaningful
information. In technical
terms, the computer is a complex machine that incorporates
diverse conceptual,
scientific, mathematical and engineering details.
The conversion of data into
information follows a well-defined model. Any activity,
natural or man-made follows
this principle, where raw material is
Input and subjected
to a Process in order to get a desired Output.
Thus we can call unorganized
facts or data, as Input , going through
an electronic
device as Process, and
meaningful information coming out of the device is termed the OUTPUT
How to start-up Computer
Ø Press System unit and Monitor power button
Ø Wait computer to operate itself
Ø If the computer has got password you have to enter or
type and if not just click OK button
Ø Computer will be started up
DATA: This is a
raw facts or basic facts awaiting input to the computer
INFORMATION: These are
already processed data or the results got after the computer has worked on.
A computer is made up of
collection of components that work together under stored instructions to
accomplish a goal. A computer accepts data from user through the input devices,
transforms this data into useful information using processing devices and
finally relays the results back to the user through the output devices.
Computers are of different
classes. Classification is done depending on the following;
- Speed of operation
- Volume of data the computer can process
- Volume of work the computer can store.
PARTS OF COMPUTER SYSTEM.
The computer system is made
up of two major parts. These are
- Computer hardware
- Computer software.
COMPUTER HARDWARE
These are the physical
components of the computer system. Computer hardware is made up of the
following parts:-
1. Input devices: For feeding
the raw material into the computer.
2. The Central Processing
Unit: For processing the inputs
3. Output Devices: That
display or produce the output.
4.STORAGE DEVICES
Definition of Hardware and Software
The computer system needs a
combination of physical parts called hardware, and
certain commands or
instructions called software that make it work.
What is hardware?
Hardware is the term used to
describe the physical components of the computer. Any
accessory or device connected
to the computer also falls in the hardware category.
What is Software?
“Software” is a set of
instructions provided to the computer to carry out the job
required by user. Without
software the computer hardware is like a dead machine, it
will be of no use.
To further understand the
concept of hardware and software, let us take the example
of a home audio system. In the
audio system, the cassette player, speakers,
microphone etc. are hardware,
even the audiocassette, constitute the hardware
because you can see and touch
them. However, the songs recorded on the
audiocassette are the
software.
Introduction to Input devices
These are devices used to
enter data into a computer. Let us see
the main input
devices used in a computer.
a) Keyboard: It is an input
device used to type in information. It has keys for the
letters of the alphabet as
well as keys for numbers, alphabet and other keys,
which perform specific
instructions.
- FUNCTION
KEYS
They
are the keys that are at the top most line of the keyboard. They are the keys
labeled F1 to F10 on the standard keyboard and F1 to F12 in enhanced or
extended keyboards. The function of these keys varies from one program to
another.
- TYPING
AREA
This
part is found at the center of the keyboard. It is constituted of alphabetic
letters labeled A to Z and numbers 0 t o9. the typing area also contain special
characters keys like :,><.=” etc.
- NUMERIC
KEYPAD
It
is the part of the keyboard which is located to the right. The numeric keypad
is used in two ways. One is to produce numbers when ON and to control cursor movement when OFF.
- TOOGLE
KEYS
They
the keys that are either ON or OFF to perform a function. They include keys
like Caps lock, Scroll Lock Num lock etc.
- MISCELENEOUS
KEYS
These
are the keys with standard use in a keyboard, or rather are keys you can never
avoid to use. They include the return/enter key, alternate, control, escape and
shift Keys.
b) Mouse
: A mouse is a pointing device about the size of palm. It is a small plastic
box with buttons on top and a
ball underneath. When a user rolls the mouse across a flat surface, the ball
rolls and a marker or mouse pointer which appears on the visual display unit
moves in the direction of the mouse’s movement. Pressing the buttons on the
mouse gives instructions to the computer.
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Microphone
c) Microphone: Microphone is also an input
device as it converts our voice signals
into digital signals and
feeds them to the computer.
d) Scanner : Scanner is an input device used to
feed/input a photograph or any
other existing physical image
such as a drawing, sketch etc into the computer.
e) The
scanner is a photocopier- like device that scans an image and sends the
image into the computer.
f) Joystick : This is an input device used to
move the cursor or any other object
on to the visual display
unit. It is usually used with video games for moving a
car or plane. A button on top
of the joystick sends commands to the computer.
Introduction to Output devices
a) Monitor: The Monitor is a
television like output device used to show the result
of any processing done by the
computer. Results of an operation can be shown
as text, numbers, or graphic
image such as charts, graphs, figures etc. Monitors
are available in many
different sizes. Like Black and white and color TVs,
monitors are available in
multicolor and in single color (monochrome).
b) Printer: The Printer is
an output device used to print the result of any
processing done by the
computer on paper. It produces printed copies of text
or graphics on paper. The
printer is used to get a “Hard Copy” of the results
i.e. it provides permanent
output (which can be viewed, filed and used at a
later stage) on the paper.
(Unlike the printer, the monitor provides us with a
soft copy of results, i.e.
the result being displayed on the monitor is not
permanent. The moment output
is changed or the power supply to the monitor
is switched off, results are
lost.)
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