This document discusses computers, data, information and communication technology (ICT). It defines a computer as a machine that processes data to produce information. Software provides instructions to computers. Computers have many advantages over humans like speed, accuracy and storage capacity. ICT relates to using electronic devices to create, store, transmit and retrieve information. Different types of ICT services and users are described. The document also discusses computer hardware, input/output devices, data storage, memory, networks and operating systems.

1. MMBUKAR
29-10-2014

2. Computers, data and information
A computer is an information processing machine.
Computers process data to produce information.
The sets of instructions that humans give computers are called
programs or software.
Software that carries out a particular type of task for a user is
often called applications software.
The three stages of computing are input, processing and
output.
A computer works through these stages by ‘running’ a
program.
A program is a set of step-by-step instructions which tells the
computer exactly what to do with input in order to produce the
required output.

3. Computers can work much faster than humans;
Computers never get tired or need a rest;
Computers can do jobs that it would be dangerous for
a human to do;
Computers can store large amounts of information in a
very small space;
Computers can find information very quickly;
Computers never lose or misplace information.
THERE ARE MANY REASONS FOR USING
COMPUTERS:-

4. Information and Communication
Technology (ICT)
 Information and Communication Technology (ICT) is the
technology required for information processing. In
particular, it relates to the use of electronic computers to
convert, store, process, transmit, and retrieve
information. It is an all-encompassing term that refers to
the devices used for creating, storing, using, or
exchanging information electronically.

5. DIFFERENT TYPES OF ICT
SERVICES/USERS
Internet services:…..shopping, office
services are becoming available online.
E-commerce:…This is the ability to
purchase goods and services online
E-banking:…online banking enable
customer to access their account via the
internet.
E-government:…this is the means by which local
and national government services are being made
available online..e.g. revenue tax collection, electronic
voting and public record systems

6. Computer Systems
Hardware is
the name that
is given to any
part of a
computer that
you can
actually touch.
An individual
piece of
hardware is
called a
device.
The basic
hardware of any
computer consists
of a central
processing unit
(CPU) along with
input, output and
backing storage
devices.

7. The system unit is the main box containing
the essential electronic parts such as
motherboard, processor, hard drive, RAM
Peripherals are all the devices that plug into
the system unit. Peripherals can be input or
output devices
Computer Systems

8. Manual Input Methods
Manual input devices are used
by people to enter data by hand.
Pointing
devices
Digital
camera
Touch screenScanner
Graphics
tablet
Microphone

9. Input and output devices are attached to computers via
ports. Each port is a socket into which a plug can be
inserted. Two of the most commonly used are
USB stands for Universal Serial Bus. Printers, keyboard
and other accessories can be attached easily to your
computer via USB port, as well as items such a
Smartphone, digital cameras and storage devices.
HDMI stands for High-Definition Multimedia interface
HDMI ports are found on digital audio devices, such as
high definition digital television, video projectors. They
connect to HDMI complaint audio and video devices, to
transmit High-definition uncompressed video and multi-
channel audio through a single cable.
INPUT/OUTPUT PORTS

10. SOME OTHER PORTS YOU MAY ALSO
USE ARE
•Serial port
•Parallel port
•Network
•Firewire port

11. Storing data
Data storage devices can be divided into 2 main
categories:
Backing storage is used to store programs and data when
they are not being used or when a computer is switched off.
When programs and data are needed they are copied into main
memory but also still remain on backing storage.
Magnetic tape drives, floppy disk drives and hard disk drives are all
examples of backing storage devices.
The Main Memory contains two types of memory chip called
ROM and RAM which hold program instructions and data.

12. BITS and BYTES
Computers store and process data using
binary numbers.
A single unit in binary is called a bit which
stands for binary digit.
Computer memory is measured in bytes.
One byte is made up of eight bits.
One byte can store one character.
1 0 0 0 0 0 1 0
The eight bit binary code in this
byte represents the letter A

13. The size of a computer’s memory is normally
measured in kilobytes (Kb), megabytes
(Mb) or gigabytes (Gb). The table below
shows some of the main units of size that we
use to measure computer memory.

14. Random Access Memory (RAM)
RAM is the computer’s ‘working memory’.
RAM temporarily stores programs and data
that are being used at a given time.
The contents of RAM can be changed and
are lost when the computer is turned off.
Memory which is wiped clean when the
computer is turned off is called volatile
memory.

15. Read Only Memory (ROM)
The main use of ROM memory chips in a computer
is to store the program that runs when the
computer is turned on which loads the operating
system (e.g. Windows 7) from disk.
The contents of ROM can’t be changed and aren’t
lost when the computer is switched off.
Memory which isn't wiped clean when the computer
is turned off is called non-volatile memory.

16. PROM and EPROM
PROM and EPROM are both special types of
programmable read only memory.
PROM stands for Programmable Read Only
Memory. This type of memory can be programmed
once but can’t be changed again afterwards.
EPROM stands for Erasable Programmable Read
Only Memory. This type of memory can be
programmed and then changed whenever
necessary.

17. Output Methods
Before any output can be produced by
a computer it must have an output
device connected to it.
The output devices that you are
probably most used to will be the
screen, or monitor, and the printer.
Another sort of output that you will
have experienced when using a
computer is sound, which is output
through a speaker.

18. Monitor
The quality of the output on a monitor depends on its
resolution.
The resolution of a monitor depends on the number of
pixels that it can display.
A monitor or screen is an output
device that can display graphics and
text and video.
The picture on a monitor is made up
of thousands of tiny coloured dots
called pixels.

19. Dot matrix printers
A dot matrix printer forms characters and graphics on
the paper by producing patterns of dots. If you look
closely at a print-out from a dot matrix printer you will
see the tiny dots which make up the printout.
The part of the printer which forms the patterns of
dots is called the print head. The print head is made
up from pins which are pushed out in different
arrangements to form the various patterns of dots
needed.

20. Inkjet printers
Inkjet printers work like dot matrix printers because the
printouts that they produce are made up of patterns of
very small dots but the print head has a set of tiny
holes rather than pins. As the print head moves across
the paper ink is forced out through the holes to form
the image.
Inkjet printers are very quiet to
operate and can produce good-
quality printouts of both
graphics and text. Relatively
cheap colour graphics can be
printed using a colour inkjet.

21. Laser printers
Laser printers give very high-quality printed output of
both text and graphics very quickly and quietly.
They are generally more
expensive to buy than
inkjet printers and the
toner cartridges are more
expensive.
They are very suitable for
large volume printouts
because of their speed.

22. Speakers
Computers can output music, voices and many other
complicated sounds using speakers.
To be able to output sound a computer needs to have a
special circuit board inside it called a sound card.
Plotters
The main difference between a plotter and a printer is
that a plotter uses a pen to draw the computer output
onto the paper.
Some plotters use a set of
coloured pens to produce
colour output. Plotters produce
very accurate drawings and are
often used in computer
aided design or CAD.

23. •To browse or ‘surf’ the Internet a browser program is required
•Microsoft Internet Explorer, Firefox , Opera, chrome and Netscape
Navigator use search engines to search for information by entering
keywords

24. •Uniform Resource Locator
•These give the location of individual sites on the World
Wide Web
•Most start with http//:www.
•They often reveal the country of origin such as .uk for
the United Kingdom. They also indicate whether the site is
commercial with either .co or .com, a government
organisation with .gov, or an academic organisation with
.ac

25. Hyperlinks
•A piece of text or a graphic that contains the address of
another location on the Web
•Creation of hyperlinks is a basic feature of any Web
design package
Hot spots
•Area on an object that contains a
hyperlink
•To create a hot spot an active area
must be defined on an object and a
hyperlink associated with it

26. •A modem converts a digital signal to an equivalent analogue signal
so that it can be sent down a telephone line.
telephone line
analogue signal
Modem ModemComputer
digital signal
01001
Computer
01001
digital signal

27. Faxes
•A fax machine scans paper documents and converts
them into digital format.
•The digital version is then converted into analogue
format and sent over an ordinary telephone line to
another fax machine.
•The fax machine at the receiving end converts the
analogue information back into digital format and
reproduces an exact hard copy of the original
document.
•Faxes are particularly useful for transferring images
such as plans, drawings or documents with
signatures between remote locations when it is
important that an identical copy of the original is
received at the other end.

28. File compression
File compression software can be used to make
files smaller so that more data can be stored in the
same amount of space on backing store.
When a compressed file on backing store needs to be
used it must be decompressed.
This can be done using decompression software or
by setting files up to be self-extracting which means
that they can automatically decompress themselves.
Winzip is an example of software that can be used to
compress and decompress files.

29. Telecommuting is when people work from home instead of
travelling to work and use methods of electronic
communication such as the telephone, fax machine, e-
mail, the Internet and videoconferencing to communicate
with the outside world.
Advantages:
Time isn’t wasted travelling to and from work;
Cars are kept off the roads which helps the environment;
Working at home is less stressful and it is much easier to concentrate;
Working hours are more flexible and can be fitted around other things
that need doing such as collecting children from school;
People who live large distances away from each other can work
together without having to meet in person;
Businesses need smaller offices and spend less on light and heating.

30.  Workers may miss the company of their co-workers
and feel isolated
 Having your workplace at home might mean that you
end up doing too much work and not having enough time
off
 It is more difficult for mangers to monitor and control
the workforce

31. Health and Safety
•Working with computers for long periods of time can
cause:
•Stress
•Eyestrain
•Wrist injuries
•Neck and back problems
•Employers can be sued
if they do not take steps to
protect employees

32. •Repeating the same physical movements over and over again can
cause a condition known as RSI
•Repeated presses on the keyboard and long periods of holding and
moving a mouse cause a build up of damage to the hands arms and
shoulders
•Spending long periods of time in front of a computer screen can
cause eyestrain
•This can be avoided by:
•Ensuring there is enough light
•Reducing the amount of glare
•Ensuring workers wear correct prescription glasses if needed

33. TYPES OF COMPUTERS
A personal computer is also known as a “PC”. It
is an affordable, stand-alone computer designed
for use by one person at a time. PCs come in
several types. Each types is suitable for different
users. The main type are listed below.
Desktops A PC
that usually sits
on, or under,
user’s desk and
is not mobile.
Laptops Portable
(PC) that is smaller
than a desktop but
larger than a tablet
PC. You can work
with it on your lap.
Good for user who
travel frequently.
Tablets A very
small, mobile,
notebook PC,

34. TYPES OF DEVICES
With advances in technology, many
handheld, portable, digital devices are
available-
Smartphone Is a mobile phone with additional
features. The extra features can include such things
s PC functionality, Internet access and multimedia
capabilities.
can play text, audio,
photos, video and graphics in a variety of formats.
Digital cameras These take digital pictures-
images which are stored in binary form, usually on a
memory card within the camera. The images can be
downloaded to a PC via for example a USB or
firewire port.

35. There are two main types of software that
are used on personal computers and
devices
Operating System (OS) software is the master
control program that keeps everything flowing
smoothly inside your computer or device. It
acts as the host for the application software on
your device.
The operating system starts-up your device. It
controls and launches software applications,
schedule tasks, allocates storage, handles the
interface to peripheral hardware.

36. THREE POPULAR OPERATING SYSTEMS
FOR COMPUTERS ARE:
•Microsoft window (with version such as
window 7, window vista and window 8)
•Apple Mac OS
•Linux
•Android
•Window phone
•iOS
•Blackberry

37. There are two main types of software
that are used on personal computers
and devices
Application software
Applications software enable users to
accomplish specific task on the computer.
Programs are available to create files such as
document, spreadsheet, presentations and
databases; in addition to task such as
communicating via the internet and playing
games. It is important to pick the right
application software for the job in hand

38. Specialist application software
Specialist application software performs a single very
specific type of task.
Programs to work out driving routes are one common
example of specialist application software.
Other examples include
programs to work out
payroll, calculate
accounts, deal with stock
control and handle
appointments.

39. Example of applications software
Word processor
•Letter, Long report and project plan
Spreadsheet
•Collect data, Collate and chart social club information and compare
forecast and actual results
Database
•Records of employees’ details, Client contact list and Resource database
Presentation
•Introduce an idea, Present result of a project and Give details of a
forthcoming product launch
Communications (e-mail)
•Correspond with clients, Communicate with friends
Web browsing
•Search for cost-effective resources, review client websites

40. SOFTWARE CAN BE ACCESSED IN A VARIETY OF
WAYS:
A program
can be
installed
locally
A program
can be
installed on
a network
A program can
be made
available
online. This
enable users to
access their
programs from
a variety of
devices, at any
time when they
have access to
the internet.

41. Social network via the internet allows groups of
people to share information and experiences
that are of interest to all the people in each
group….Below are some examples of social
networking sites.
•Facebook
•Twitter
•Google+
•MySpace
•Bebo
•Friend Reunited

42. Network Concepts
A network is a collection of several computers
connected together, so they can securely share
and access files (documents and applications),
data and resources ( for example printer), as well
as being able to communicate electronically.
A client/server network is the most efficient way
to connect multiple computers to share
information
• The server is the central computer that stores
everyone’s files.
• A client is any computer that can access the
information stored on the server.

43. TYPES OF COMPUTER NETWORKS
Local Area Network (LAN) LANs are usually
confined to a small geographic area, such as an
office or building.
Wireless Local Area Network (WLAN) is a
LAN where the computers and equipment are
connected wirelessly-using a router to transmit
data between equipment
Wide Area Network (WAN) A WAN connects
computers across a large geographic area. Such
as a city or country. The internet is an example
of WAN

44. INTERNET
The word internet comes from the phrase “
Interconnection of networks”. It is the biggest computer
network in the world, reaching millions of people, on
thousand of interconnected networks. No one person or
group controls the internet, so finding a particular piece of
information can be challenging.
World Wide Web (WWW) can be used to access the
information that sits on the internet. You can use the
communication structure of cables and satellites that makes
up the internet globally, to access the web via a browser.

45. Intranets and VPNs are networks with a
specific purpose
An intranet is a computer network used within one company
or organisation. It has limited access and usually provides a
similar look and feel to the Internet. It is a private network.
Virtual Private Network (VPN) A VPN is a network that
allows users who are not connected directly to their
organisation’s network ( for example through a LAN or WAN)
to connect to that network and access the computers, drives
and folders to which they have logon rights. The data sent
and received via this connection will be encrypted, so it
cannot be read by anyone who attempts to intercept it.

46. ACCESSING THE INTERNET
It is possible to connect to the internet via a variety of options.
•Phone line this can give you access to ADSL broadband.
•Mobile phone can use mobile phone network to connect to
the internet
•Cable – cable operator offer broadband service via their high
speed fibre-optic cables.
•Wi-fi – wi-fi uses radio frequencies, rather than cable &
telephone line.
•Wi-max – is a wireless broadband tech that has a much
greater range that wi-fi -…its range may be as much as 25 mile
•Satellite-for home or businesses located in remote areas.

47. Questions