2. Computer
an electronic device for storing and processing
data, typically in binary form, according to
instructions given to it in a variable program.
3. Computer
1. It responds to a specific set of instructions in a well-defined manner.
2. It can execute a prerecorded list of instructions (a program).
3. It can quickly store and retrieve large amounts of data.
Characteristics of Computer
5. Hardware
The collection of physical parts of
a computer system. computer case, monitor,
keyboard, and mouse. It also includes all the
parts inside the computer case, such as the hard
disk drive, motherboard, video card, and many
others. Computer hardware is what you can
physically touch.
7. Central Processing Unit (CPU)
The heart of the
computer, this is the
component that actually
executes instructions
organized in programs
("software") which tell
the computer what to
do.
9. Mass Storage Device (MSD)
Allows a computer to permanently retain large
amounts of data and programs between jobs.
Common mass storage devices include disk drives
and tape drives.
10. Input Devices
Usually a keyboard and mouse, the input device is the
conduit through which data and instructions enter a
computer.
11. Input Devices
Usually a keyboard and mouse, the input device is the
conduit through which data and instructions enter a
computer.
Keyboard Mouse Joy Stick
Light pen Track Ball Scanner
Graphic Tablet Microphone Magnetic Ink Card Reader(MICR)
Bar Code Reader Optical Mark Reader(OMR) Optical Character Reader(OCR)
12. Input Devices
1. Keyboard is the most common and very popular input device
which helps in inputting data to the computer. The layout of the
keyboard is like that of traditional typewriter, although there are
some additional keys provided for performing additional
functions.
2. Mouse is most popular pointing device. It is a very famous
cursor-control device having a small palm size box with a round
ball at its base which senses the movement of mouse and sends
corresponding signals to CPU when the mouse buttons are
pressed.
3. Joystick is also a pointing device which is used to move cursor
position on a monitor screen. It is a stick having a spherical ball
at its both lower and upper ends. The lower spherical ball moves
in a socket. The joystick can be moved in all four directions. Use
in Computer Aided Designing.
13. Input Devices
4. Light pen is a pointing device which is similar to a pen. It
is used to select a displayed menu item or draw pictures on
the monitor screen.
5. Track ball is an input device that is mostly used in
notebook or laptop computer, instead of a mouse. This is a
ball which is half inserted and by moving fingers on ball,
pointer can be moved.
6. Scanner is an input device which works more like a
photocopy machine. It is used when some information is
available on a paper and it is to be transferred to the hard
disc of the computer for further manipulation. Scanner
captures images from the source which are then converted
into the digital form that can be stored on the disc.
14. Input Devices
7. Digitizer is an input device which converts analog information into
digital form. Digitizer is also known as Tablet or Graphics Tablet
because it converts graphics and pictorial data into binary inputs. A
graphic tablet as digitizer is used for doing fine works of drawing and
image manipulation applications.
8. Microphone is an input device to input sound that is then stored
in digital form. The microphone is used for various applications like
adding sound to a multimedia presentation or for mixing music.
9. MICR input device is generally used in banks because of a large
number of cheques to be processed every day. The bank's code
number and cheque number are printed on the cheques with a
special type of ink that contains particles of magnetic material that
are machine readable. This reading process is called Magnetic Ink
Character Recognition (MICR). The main advantages of MICR is that
it is fast and less error prone.
15. Input Devices
10. Optical Character Reader is an input device used to read a
printed text. OCR scans text optically character by character, converts
them into a machine readable code and stores the text on the system
memory.
11. Bar Code Reader is a device used for reading bar coded data
(data in form of light and dark lines). Bar coded data is generally used
in labelling goods, numbering the books etc. It may be a hand held
scanner or may be embedded in a stationary scanner. Bar Code
Reader scans a bar code image, converts it into an alphanumeric
value which is then fed to the computer to which bar code reader is
connected.
12. Optical Mark Reader is a special type of optical scanner used to
recognize the type of mark made by pen or pencil. It is used where
one out of a few alternatives is to be selected and marked. It is
specially used for checking the answer sheets of examinations having
multiple choice questions.
16. Output Device
1. A display screen, printer, or other device that lets you see
what the computer has accomplished.
2. Any peripheral that receives data from a computer, usually
for display, projection, or physical reproduction. For example,
the image shows an inkjet printer, an output device that can
make a hard copy of any information shown on your monitor.
17. MONITOR
Monitors, commonly called as Visual Display Unit
(VDU), are the main output device of a computer.
It forms images from tiny dots, called pixels that
are arranged in a rectangular form. The sharpness
of the image depends upon the number of pixels.
18. TYPES OF MONITORS
CRT (CATHODE RAY TUBE)
LCD (LIQUID CRYSTAL DISPLAY)
LED (LIGHT EMITTING DIODE)
19. Cathode-Ray Tube (CRT) The CRT
display is made up of small picture
elements called pixels. The smaller the
pixels, the better the image clarity, or
resolution. It takes more than one
illuminated pixel to form whole
character, such as the letter ‘e’ in the
word help.
20. LCD MONITOR
A liquid-crystal display (LCD) is a flat-panel
display or other electronic visual display that uses
the light-modulating properties of liquid crystals.
Liquid crystals do not emit light directly. LCDs are
available to display arbitrary images (as in a
general-purpose computer display) or fixed
images with low information content, which can
be displayed or hidden, such as preset words,
digits, and 7-segment displays, as in a digital
clock. They use the same basic technology, except
that arbitrary images are made up of a large
number of small pixels, while other displays have
larger elements.
21. LED MONITOR
An LED display is a flat panel display,
which uses an array of light-emitting
diodes as pixels for a video display.
Their brightness allows them to be used
outdoors in store signs and billboards,
and in recent years they have also
become commonly used in destination
signs on public transport vehicles. LED
displays are capable of providing
general illumination in addition to
visual display, as when used for stage
lighting or other decorative (as opposed
to informational) purposes.
22. GRAPHIC PLOTTER
The plotter is a computer printer for
printing vector graphics. In the
past, plotters were used in applications
such as computer-aided design, though
they have generally been replaced with
wide-format conventional printers.
A plotter gives a hard copy of the output. It
draws pictures on a paper using a pen.
24. DRUM PLOTTERS
A drum plotter is also known as Roller Plotter. It consists of a
drum or roller on which a paper is placed and the drum rotates
back and forth to produce the graph on the paper. It also consists
of mechanical device known as Robotic Drawing Arm that holds a
set of colored ink pens or pencils.
Use in blue prints (CAD)
25. FLATBED PLOTTERS
A flatbed plotter is also known as
Table Plotter. It plots on paper that is
spread and fixed over a rectangular
flatbed table. The flatbed plotter uses
two robotic drawing arms, each of
which holds a set of colored ink pens
or pencils. The drawing arms move
over the stationary paper and draw
the graph on the paper.
29. IMPACT PRINTERS
The impact printers print the characters by striking
them on the ribbon which is then pressed on the
paper.
Characteristics of Impact Printers are the following:
• Very low consumable costs
• Very noisy
• Useful for bulk printing due to low cost
• There is physical contact with the paper to
produce an image
31. CHARACTER PRINTERS
DOT MATRIX PRINTER
In the market one of the most popular printers is Dot Matrix Printer.
These printers are popular because of their ease of printing and
economical price. Each character printed is in form of pattern of dots
and head consists of a Matrix of Pins of size (5’7, 7’9, 9’7 or 9’9) which
come out to form a character that is why it is called Dot Matrix Printer.
DAISY WHEEL
Head is lying on a wheel and pins corresponding to characters are
like petals of Daisy (flower name) that is why it is called Daisy
Wheel Printer. These printers are generally used for word-
processing in offices which require a few letters to be sent here
and there with very nice quality. It is like a typewriter.
32. LINE PRINTERS
Line printers are the printers which print one line at a time.
DRUM PRINTER
This printer is like a drum in shape so it is called drum printer.
The surface of drum is divided into number of tracks. Total
tracks are equal to size of paper i.e. for a paper width of 132
characters, drum will have 132 tracks. A character set is
embossed on track. The different character sets available in
the market are 48 character set, 64 and 96 characters set.
One rotation of drum prints one line. Drum printers are fast in
speed and can print 300 to 2000 lines per minute.
CHAIN PRINTER
In this printer, chain of character sets are used so it is called
Chain Printer. A standard character set may have 48, 64, or 96
characters.
33. NONE IMPACT PRINTERS
Non-impact printers print the characters without
using ribbon. These printers print a complete page at
a time so they are also called as Page Printers.
Characteristics of Non-impact Printers
Faster than impact printers.
They are not noisy.
High quality.
Support many fonts and different character size.
35. Laser Printers These are non-impact page printers. They
use laser lights to produce the dots needed
to form the characters to be printed on a
page.
ADVANTAGES
Very high speed
Very high quality output
Give good graphics quality
Support many fonts and different character size
DISADVANTAGES
Expensive.
Cannot be used to produce multiple copies of a
document in a single printing.
36. Inkjet Printers
Inkjet printers are non-impact character
printers based on a relatively new technology.
They print characters by spraying small drops of
ink onto paper. Inkjet printers produce high
quality output with presentable features.
They make less noise because no hammering
is done and these have many styles of
printing modes available. Colour printing is
also possible. Some models of Inkjet printers
can produce multiple copies of printing also.
ADVANTAGES
High quality printing
More reliable
DISADVANTAGES
Expensive as cost per page is high
Slow as compared to laser printer
38. PROJECTOR
A projector or image projector is an optical device that
projects an image (or moving images) onto a surface,
commonly a projection screen.
Most projectors create an image by shining a light through
a small transparent lens, but some newer types of
projectors can project the image directly, by using lasers.
A virtual retinal display, or retinal projector, is a projector
that projects an image directly on the retina instead of
using an external projection screen.
39. TYPES OF PROJECTORS
CRT PROJECTOR
DLP PROJECTOR
VIDEO PROJECTOR
LCD PROJECTOR
LED PROJECTOR
LCoS PROJECTOR
40. CRT PROJECTOR
A CRT projector is a video projector that uses a small, high-brightness cathode
ray tube as the image generating element. The image is then focused and
enlarged onto a screen using a lens kept in front of the CRT face. The first
color CRT projectors came out in the early 1950s. Most modern CRT
projectors are color and have three separate CRTs (instead of a single, color
CRT), and their own lenses to achieve color images.
41. DLP PROJECTOR
Digital Light Processing (DLP) is a display device based
on optical micro-electro-mechanical technology that
uses a digital micromirror device. DLP is used in a
variety of display applications from traditional static
displays to interactive displays and also non-
traditional embedded applications including medical,
security, and industrial uses.
42. VIDEO PROJECTOR
A video projector is an image projector that
receives a video signal and projects the
corresponding image on a projection screen using
a lens system. All video projectors use a very
bright light to project the image, and most
modern ones can correct any curves, blurriness,
and other inconsistencies through manual
settings. Video projectors are widely used for
many applications such as conference room
presentations, classroom training, home
theatre and concerts. Projectors are widely used
in many schools and other educational settings.
43. LCD PROJECTOR
An LCD projector is a type of video projector for displaying video, images or computer
data on a screen or other flat surface. It is a modern equivalent of the slide
projector or overhead projector. To display images, LCD (liquid-crystal display)
projectors typically send light from a metal-halide lamp through a prism or series
of dichroic filters that separates light to three polysilicon panels – one each for the
red, green and blue components of the video signal. As polarized light passes through
the panels (combination of polarizer, LCD panel and analyzer), individual pixels can be
opened to allow light to pass or closed to block the light. The combination of open
and closed pixels can produce a wide range of colors and shades in the projected
image.
44. LED PROJECTOR
A TV projector that uses LEDs for its light source. See data projector and front-
projection TV.
LED projectors are becoming more and more popular. LED technology is being
used in a wide range of products, including home theater projectors, business
and education projectors, and even the emerging market of Pico
projectors, and other mini projector systems. This has its benefits in a variety of
fields, with several different uses.
45.
46. Computer speaker
Also known as multimedia speakers, are speakers sold for use
with computers, although usually capable of other audio uses,
e.g. for an MP3 player.
47. Types of Speakers
TWO-SPEAKER SYSTEM
2.1 SPEAKER
5.1 SPEAKER
7.1 SPEAKER
Wireless SPEAKER
49. Headphones are a pair of small listening devices that are designed
to be worn on or around the head over a user's ears. They
are electroacoustic transducers, which convert an electrical
signal to a corresponding sound in the user's ear. Headphones are
designed to allow a single user to listen to an audio source
privately, in contrast to a loudspeaker, which emits sound into the
open air, for anyone nearby to hear. Headphones are also known
as earspeakers, earphones or, colloquially, cans. Circumaural and
supra-aural headphones use a band over the top of the head to
hold the speakers in place.
50. Types of Headphones
CLIP-ON HEADPHONES
BEHIND THE NECK HEADPHONES
NOISE CANCELLING HEADPHONES
HEADPHONES WITH MICROPHONE
51. NOISE CANCELLING HEADPHONES
These types of headphones excel
in cancelling external noise to a
greater extent. Almost by 90%!
They are designed in such a way
that…
...ambient noise gets reduced by a
larger margin when you wear
them on.
53. Software
a generic term for organized collections
of computer data and instructions, often broken
into two major categories:
1. System Software that provides the basic
non-task-specific functions of the computer.
2. Application Software which is used by
users to accomplish specific tasks.
54. System
Software
1) Microsoft Windows
2) Linux
3) Unix
4) Mac OSX
5) DOS
6) BIOS Software
7) HD Sector Boot Software
8) Device Driver Software i.e Graphics
Driver etc
9) Linker Software
10) Assembler and Compiler Software
55. Application
Software
Examples :
Web browser, word processing software, spreadsheet
software, database software, presentation graphics
software.
1) Opera (Web Browser)
2) Microsoft Word (Word Processing)
3) Microsoft Excel (Spreadsheet software)
4) AutoCAD 2007 (Engineering Software)
5) MySQL (Database Software)
6) Microsoft Powerpoint (Presentation Software)
7) iTunes (Music / Sound Software)
8) VLC Media Player (Audio / Video Software )
9) World of Warcraft (Game Software)
10) Adobe Photoshop (Graphics Software)
56. Firmware
A program that's written to the read-only memory
(ROM) of a computing device. Also known as
embedded software and example of this is
microcontroller.
Arduino Microcontroller
57. Quiz
1. Define Computer (3 points)
2. Give 1 characteristic of Computer (2points)
3. Give the 3 parts of Computer (3 points)
4. Give 3 Hardware of Computer (3 points)
5. Give 2 Input Device (2 points)
6. Give 2 Output Device (2points)
7. Give the 2 types of Software (2 points)
8. Give 3 examples of Application Software (3 points)
