Summary Notes
TERM THREE
BASIC SEVEN
(7)
ACADEMIC YEAR 2014
BASIC TYPING SKILLS
DEVEKOPMENT
MANIPULATIVE KEYS ON THE KEYBORD
The computer keyboard has been divided
into four main sections for ease of use. They
are;
•Alphanumeric keys
•Functional keys
•Navigation/special keys
•Numeric keys
MANIPULATIVES KEY
Manipulative keys are non-printing characters
that are used to change the
appearance and layout of text on any page.
Examples;
a. the Shift Key
b. the Caps Lock Key
c. the Enter Key
d. the Backspace Key
e. the Tab Key
f. the Delete
g. the Insert key
FUNCTIONS OF THE KEYS
 THE SHIFT KEY – is used in combination with
other keys to produce uppercase letters during
typing.
 THE CAPS LOCK KEY – produces uppercase
letters when pressed.
 THE ENTER KEY – is used to move the insertion
point to next line when typing and also executes
a command in an operation.
 THE BACKSPACE KEY – is used to delete
characters to the left of the insertion point.
 THE DELETE KEY – is used to delete characters to
the right of the cursor.
COMMON KEYBOARD SYMBOLS
• It is impossible to write meaningful passages
without punctuation. The keyboard offers
several symbols and punctuations to help you
produce meaningful and excellent documents.
• Punctuation marks are symbols used to organise
writing and edit document. They are the
standard non alphabetical symbols or marks that
are used to organise writing into clauses,
phrases, and sentences, and in this way make its
meaning clear. Keys on the keyboard with these
marks are called punctuation keys.
The following are some of the punctuation
marks we will be considering;
• Comma (,)
• Full stop (.)
• Slash (/)
• Semi-colon (;)
Functions of the punctuation marks.
• Comma: A punctuation mark (,) that represents
a slight pause in a sentence or is used to
separate words and figures in a list.
• Slash: A slash (/) is a punctuation mark that is
used to separate optional items in a list or to
express fraction or division, it also has various
uses in computer programming. The slash is
also known as virgule or forward slash.
• Full stop: Complete stop or a complete halt or
an end (.)
• A semi colon (;) is used to
separate two parts of a sentence
that have a relationship to each
other in terms of meaning when
each part could stand alone as a
sentence in its own right.
• Keyboard Symbols
Symbol keys not requiring shift
• ` Left single quote
• - Dash
• = Equal sign
• [ Left (opening) square bracket
• ] Right (closing) square bracket
• \ Backslash
• ; Semi-colon
• ‘ Apostrophe
• , Comma
• . Period
• / Slash or Diagonal
Symbol keys requiring shift
• ~ Tilde
• !
Exclamation point
• @ At symbol
• # Number or Pound sign(hash)
• $ Dollar sign
• % Percent sign
• ^ Caret symbol
• & Ampersand
• * Asterisk
• (
Left (opening) parenthesis
• )
Right (closing) parenthesis
• _ Underscore
• + Plus sign
•
•
•
•
•
•
•
•
{ Left (opening) bracket
} Right (closing) bracket
| Pipe symbol
: Colon
“”
Quotation marks
< Less than symbol
> Greater than symbol
? Question mark
GRAPHICAL USER INTERFACE
(GUI)
DESKTOP
Definition:
The desktop screen or the graphical
user interface is the colourful
workspace that appears after the
computer has gone through its
booting process.
FEATURES OF THE WINDOWS DESKTOP
• The graphical user interface differs
from one operating system to
another. Below are some examples
of the computer desktop.
Windows XP desktop
Windows 7desktop
ICONS
START BUTTON
TASK BAR
NOTIFICATION AREA
Windows 8 desktop and start screen
 Icons: Icons are graphical representation of
programs, files, folders and drives on the
computer desktop.
 Wallpaper: The wallpaper is the
background pattern for a computer screen.
 Every window comes with pictures that can
be used as wallpaper. Moreover, the user
can also select his / her own picture to use as
a wallpaper provided that one is saved in the
computer.
FEATURES OF THE DESKTOP
COMPUTER / MY
COMPUTER ICON
MY DOCUMENT ICON
•
It
is
the
shortcut
to
a
• Computer icon lets the
ready-made
folder
user browse the files
on your computer’s
stored on the PC.
hard disk. My
• Double-clicking on this
Documents icon
icon shows the hard
contains all the
disk, the floppy disk,
documents saved on
the CD-ROM drive and
the computer
the possible drives
without specifying
installed in the
its location.
computer system.
RECYCLE BIN
• It is an electronic container
that keeps temporary
deleted files and folders.
• Moreover, the deleted files
or documents can be
restored back if wanted.
• Note that when the user
empties the recycle bin,
anything that its holds will
be deleted permanently.
THE INTERNET EXPLORER
The internet
connection wizard is a
special program called
a browser which
interpret content of a
web page and helps the
user to navigate web
pages on the internet.
A Folder
Network icon
• The network icon helps
the user to connect to
• A folder is an
other computers on the
electronic storage
area use to organize network. It is a utility
for browsing network
files, programs and
resources like the
other folders.
shared files, web links
and networked local
printers.
Taskbar
The taskbar is the
horizontal bar usually
located at the bottom
of the desktop window.
The taskbar has four
main sections.
– The Start button
which is used to
launch programs.
– The Quick Launch
toolbar is used to
quickly load
programs.
- The middle section
which shows tabs of
all programs and files
opened and allows to
switch between them.
- The notification area
which includes a clock
and icons that show
the status of certain
programs and
computer system.
 USING START MENU
 USING ICONS ON
THE DESKTOP
THE START MENU
• The Start menu gives the user access
to navigate through the system.
• The left pane of the start menu
shows a list of programs we use
frequently while the right pane
displays system options, folders,
shortcuts, the name and the picture
that represents the current user.
• FIGURE OF THEE START MENU
Picture of the user
Name of the user
Accessories
folder
Items under
Accessories
STEP 1 LAUNCHING AN APPLICATION
USING THE START MENU
•The technical term for opening
an application is launch or
load.
• To launch an application using the Start menu,
observe the following steps:
1. Click on the Start button located on the taskbar to
display its menu. (Figure below)
Start menu
Start button
• Click on a desired program name in left
pane. If in any way, the desired program
could not appear, click on All Programs
and scroll through the list. Moreover, the
user can also type the name of the
program in the search box and press on
the Enter key to display the search
results.
•NB: The folders shown in All Programs
list contain other programs. For example
the WordPad, Paint, Calculator and Note
Pad are under Accessories
STEP 2. LAUNCHING ANA PPLICATION
USING DESKTOP ICONS
• Desktop icons provide a shortcut to launch
programs and open folders.
• To launch any program using the desktop
icons, use the following methods:
1. Method 1: Double-click the program
shortcut icon on the Windows Desktop to
launch it.
• 2. Method 2: Click the program icon on
the Windows desktop and press Enter
key on the keyboard.
• 3. Method 3: Right click the program
icon on the desktop.
In the drop-down menu or list of items,
click on Open to launch the program.
CREATING A SHORTCUT OF A PROGRAM ON
THE DESKTOP.
•To create a shortcut for a program on the
desktop, the user may use any of the
following methods.
•Click on the Start button on the taskbar to
display the start menu.
•Click on All Programs to display most of the
programs and right click on the desired
program.
•Click on (create shortcut) to send the
program icon to the desktop.
APPLICATION WINDOWS
• Programs and folders open in their own
windows. These windows have certain
characteristics in common.
• A window is an area within a frame on
the desktop screen in which a program
operates or information is displayed.
TYPES OF WINDOWS
MICROSOFT WORD
APPLICATION WINDOW
FOLDER WINDOW
THE TITLE BAR
• The title bar is a horizontal bar at the top of a window.
This bar contains the name of the program and control
buttons that are used to close or minimize the window.
Elements or features of the title bar
• The title bar can be divided into two main sections. The
first section of the bar shows details of the program in use.
• A program icon or logo is the first item. This is the logo
that the makers of the program have given the program as
its unique identifier.
• The second item on the title bar is the name of the active
file. This can also be called the file name or document
name. Application programs are used to create files and
most programs we use create files.
By default, when an application program is launched
it create a blank file with a temporary name until the
user saves it with a file name.
• The program name or application name/title is the last
part of the first section of the title bar.
• Control Box
The second section of the title bar is termed as the
Control Box. This box contains three buttons namely
– the minimize button
– the maximize/restore button
– the close button
CONTROL BOX BUTTONS
• The minimize button
• The maximize button/Restore button
• The Close button
• The Minimize button is used to suspend or hide a
window and reduce the window to a button on the
taskbar. This button also allows a user to keep a
program running in the background, so he/she can
concentrate on other things.
• The Maximize/Restore Down button
The Maximize is used to expand a window to
its biggest size possible. The Restore down
button replaces the Maximize button when
a window is fully maximized.
• The Close button
The Close Button is used when a user want
to close or exit out of a window. This button
closes a program and every file that was
open in that particular program.
• THE CONTEXT MENU
The Context Menu is a pop-up menu
that appears when you right-click on
the title bar of a window. This menu
gives the user other ways of
managing a window. Right-clicking
on the title bar of a window gives the
user an additional way of
minimizing, maximizing/restoring,
moving and closing a window.
LEARNING WITH ICT TOOLS
• Information and Communications Technology
tools have become a part of everything we do.
From health to education, entertainment and
work and even in our everyday social life, we
make use of ICT.
• Learning with tools can be done many ways.
Students have been using these tools everyday in
their schools to assist them in accessing an
sharing information. Teachers also use them for
the same purpose.
The following are the various ways
ICT tools are use to learn.
•
•
•
•
•
Accessing information
Sharing ideas
Computing calculations
Storing information
Processing and displaying
information
How ICT tools Support Learning
Learning is a term that is used to describe a
situation where a person or thing has
acquired some knowledge and is able to apply
the it in situations that are able to solve
problems.
Key issues in the learning process include
access to information and the medium that is
used to communicate such information.
ICTs support learning in many different areas.
Teaching
• In most formal educational set ups,
learning is as a results of structured
teaching. ICTs are a big part of teaching.
Several different ICT tools available that
are used in teaching. There are tools such
as overhead projectors, LCD projectors,
television, electronic boards, public
address systems, and computers which are
directly used in transferring knowledge to
different students.
Teaching ICT tools
Overhead projector
LCD projector
Projector screen
Projector screen
Research
Research is an important part of training. ICTs play a
very important role in research. In science, many
new ways of collecting and testing data has become
possible because of ICT. Unmanned mission to Mars
has become possible because of ICT tools like
‘Opportunity ,a robot, have successfully conducted
experiments and sent result to earth. Teachers and
student alike are able to have access to a lot of
reading material through the internet. Libraries are
able to stock up with electronic journals, even when
they do not have the physical space to stock these
volumes.
ICT tools for research
Internet page
Mars Rover – Opportunity
Knowledge Sharing
• Now more than ever before, learners from all over
the world are able to share ideas and information.
Because of I C Ts such as the internet, TV, radio and
telephone, people are able to get together easily to
explore and debate in groups. Learning has therefore
become richer since there is the opportunity to hear
what people from completely different background
have to say about any particular issue. The use of
mobile phones has become extremely popular and
common in all places.
Accessing Information
• The computer, television and radio are some of the media
through which information is made readily accessible. It
is particularly useful for students in deprived areas since
this comes at little or no cost. The President’s special
Initiative on Education, for example, airs on national
television. The computer and Internet has also
contributed and continues to contribute immensely by
providing easy access to information through the help of
internet search engines, which are tools that allow you to
search and find almost any type of in formation you need.
Information on educational CDs are also of immense use.
Software such as Encarta and Britannica are some
examples.
Learner Support
• Learners need support and assistance as they go through
their learning process. ICT tools such as calculator,
sound recorders, computers and mobile phones provide
this much needed support. Complex mathematical
calculations can be made easy and simple by calculators,
and important lectures may be recorded on the audio
recorder for future reference.
Digital audio recorders
School Administration
• A large part of learning takes place in
school. School administration provides the
needed support to ensure that learning goes
on smoothly. This they do by scheduling
classes, registering students, compiling staff
rosters and also any general office
administration such as typing letters and
sending e-mails. These duties are performed
with tools such as computers, PDAs and
mobile phones.
Personal Digital
Assistance
Simulation & Experiment
• One of the most exciting ways that ICTs aid learning is
in the area of experiment and simulation. Several ICT
tools (especially in the area of computers) have been
developed that can be used to simulate experiments
that may be too dangerous or expensive. These allow
for students and trainees to go though the learning
experience without putting themselves in danger. This
method is sometimes used to train police drivers on
how to drive police cars.
PA systems
PA systems
Personal Digital Assistance
Portable audio recorders
SUMMARY NOTES
It covers the following:
• HAZARDS
Radiation
Glare
Repetitive Strain Injury
Contamination/Pollution
Addiction
Electrical Shock and Fire outbreak
• SAFETY PRECAUTIONS IN THE USE OF ICT TOOLS
RADIATION
Radiation refers to a type of energy that is emitted in
the form of waves . These waves come from everyday
ICT gadgets that you use. The most common of these
are mobile phones and microwave ovens . Health
experts suggest that long term exposure to this type of
radiation may lead to several health problems. These
problems include
• Headache
• Dizziness
• Nausea
• Sleep deprivation
• Cancer
Some ICT Tools that emit Radiation
GLARE
Glare refers to over illumination or light pollution.
Most Visual Display Units (VDU) use high intensity
light to display images correctly. When you sit
behind these screens for a long time, our eyes
get tired from the light that these screens emit. Glare
also results in health problems such as
• Headaches
• Eye irritation
• Loss of eye sight.
Repetitive Strain Injury (RSI)
Repetitive strain injury is a health problem that is caused by the
constant use of ICT tools. This causes the muscles in the upper
body to become sore as a result of keeping them tense over long
periods. When you perform repetitive tasks over a long period
the muscles become tired and begin to ache. Computer users
tend to suffer this symptom regularly. This type of health is
attributed to poor posture and repetitive motions. RSI cause
problems such as:
• Recurring pain or soreness in neck, shoulders, upper back, wrists
or hands.
• Tingling, numbness, coldness, or loss of sensation.
• Loss of grip strength, lack of endurance, and weakness.
• Muscles in the arms and shoulders feel hard.
• Pain or numbness while lying in bed.
The diagram of the palm
and wrist
Typing for a long time
causes RSI.
Using the mouse for long time causes RSI.
CONTAMINATION/POLLUTION
Pollution is the introduction of undesirable materials into
the environment. Some ICT gadgets you use produce
contaminants constantly. Such contaminants may be
harmful to humans when inhaled. Laser printers and
photocopiers release toner into the atmosphere. These
over a long period can lead to disease. Some other gadgets
also produce noise pollution. Some of the problems that
pollutants cause include:
 respiratory disorders
Cardiovascular (heart) problems
Hearing loss
High blood pressure
Discarded computers that can cause
contamination/pollution to our health
ADDICTION
Addiction can be explained as an obsessive and
uncontrollable need to use something. Because of exciting
nature of ICT tools, there is a growing problem of people
becoming addicted to them. There are millions of people
who sit by the computers for many hours and cannot get
away from it, sometimes even to eat or talk with their
family members. Some symptoms of addiction are:






craving time to spend on gadgets
over joy when at the computer
inability to stop ICT activity
getting angry quickly when not using ICT tools
neglect of family and friends
problems at work or school
An addicted computer user
ELECTRICAL SHOCK/FIRE OUTBREAK
Most ICT tools need some form of power to operate
well. There are a lot dangers associated with the use of
electricity. Faulty gadgets can lead to electrical shocks
that can harm humans. Also they can cause fire that
can destroy a lot of properties and kill humans
Safety Precautions in the use of ICT Tools
Despite all the problems enumerated above,
ICT tools provide so much advantage and use
for us that you have to find a way to
overcome these problems and take advantage
of the numerous services that ICT’s provide.
RADIATION
1. Radiation can be reduced by constantly
checking with manufacturers for a newer
version of our product that emit less
radiation.
The Radiation symbols
2. We can also keep items that produce radiation
farther away from us.
GLARE
1. Glare can greatly be reduced by acquiring anti glare
shields for computer screens.
2. Always adjust the brightness level of the visual display
unit to a level that your eyes will tolerate.
3. Adjust your seating position so that you are not sitting
too close to the screen
4. Ensure there is proper lighting in the room where you
use ICT gadgets.
5. Take frequent breaks and look at other things, so
your eyes can take a well deserved rest.
REPETITIVE STRAIN INJURY
1. Take frequent breaks and exercise your
hands and wrist. This will ensure proper
circulation of blood and muscle movement.
2. Place a writ rest between your
keyboard and the edge of your desk.
3. Don’t place your mouse at the edge of the
desk.
4. Reduce the number of times that you have
to take your hand off the keyboard to the
mouse
A diagram of correct position in
front of the computer
Contamination/Pollution
1. Good ventilation is the key to avoiding
unnecessary exposure to pollutants.
Where there is adequate circulation, the
risk of inhaling excessive pollutants is
reduced, since there is enough air to
dissipate the concentration of pollutants.
2. Check to make sure that your gadgets do
not have any leaks.
ADDICTION
Addiction is very difficult vice to curb. Try not
to be pre-occupied by a tool all the time
1. Take breaks and attend to other social
issues
2. If you notice that somebody is staying on a
tool all the time, try to get them away for a
while. Engage them in conversation and
draw their attention to your observation.
3. Experts be invited to assist those who are
already addicted.
ELECTRICAL SHOCK AND FIRE HAZARDS
In order to avoid electrical problems and
fire, you need to very cautious about
how we connect our gadgets.
1. Do not overload electrical sockets.
2. Avoid eating and drinking near ICT
tools.
GREEN COMPUTING
Protecting the environment has become a very important issue
to human life. In Ghana, energy has become a vital commodity
in the last few years. It important to adopt healthy measures in
our use of ICT tools, to help conserve energy and hence
contribute to improve the energy situation.
1. When you are not using computers, you need to make sure
that they have been properly turned off.
2. When buying new computers, you should ensure that they
comply with the Energy Star program a program that
certifies computers as energy efficient or not.
3. Print sparingly. Only print items that you need and recycle
paper as much as you can.
INTERNET AND WORLD WIDE WEB(WWW)
Internet is a world wide interconnection of
networks. Internet is a world wide collection of
networks that use the internet protocol (IP) to
communicate with a very powerful data
transmission systems such as GPRS, Telephone
lines, Satellite, Modem and EDGE.
A home computer may be linked to the internet
using a phone line modem, DSL or Cable Modem
that talks to an Internet Service Provider(ISP)
such as ZipNet, Africa On Line, Vodafone, MTN,
Zain, etc. A computer in a business or Collage will
usually have a network interface card(NIC) that
directly connects to a local area
network(LAN) inside the business or use a
modem which is connected to a telephone
line. ISP’s then connect to a larger ISP’s and
the largest ISP’s maintain fiber-optic
“backbones” for an entire nation or region.
Backbones around the world are connected
through fibber-optic lines, undersea cables
or satellite links.
The internet carry services such as file
transfer, online chat, email, and the popular
World Wide Web.
It began in 1980’s when physicist Dr.
Berners-Lee wrote a small computer
program for his own personal use. This
program allowed pages, within his
computer, to be linked together using
keywords. It soon became possible to
link documents in different computers,
as long as they were connected to the
internet. The document formatting
language used to link documents is
called HTML( Hypertext Markup
Language)
Prepared by Sir Lexis Oppong
The internet
Figure 1.0: The Internet Connections
WORLD WIDE WEB(WWW)
The World Wide Web is an interconnection
of documents(called hypertext) across the
internet. These web pages may contain text,
audio, images and video.
Some times people use the words Internet
and World Wide Web(www) synonymously
but they are different.
The WWW is a component of the internet
that present information in graphical
interface while Internet is the physical
structure of the network.
Prepared by Sir Lexis Oppong
The www refers to the only one resource – a
collection of documents called web pages
available through the internet.
Figure 1.1: The World Wide Web
Prepared by Lexis Oppong
ADVANTAGES OR USES OF THE WEB
• Performing research: The WWW provides access
to a vast amount of research material, including
resources from libraries, museums, and research
institutions, i.e. Microsoft Encarta.
• Chatting: Some online service providers enable
their users to talk in real time with each other while
they are on line through the use of chat room and
instant messaging.
Prepared by Joachim Konyo
• Obtaining News: Many media groups have website that
provides latest news headlines and newspaper reviews.
Joy FM, Citi FM, Adom FM, CNN, BBC are just a few
examples.
• Downloading Software: The availability of freeware,
shareware and commercial software on the internet
makes it easy to download such wares from many
website.
• Distance learning: There are special courses on line
from universities and other centers of higher learning to
be pursued without the physical presence of the student
at the campuses.
• Arranging travel plans and checking exams results.
• Shopping: There are website with links to online
merchants that can meet your needs. Indeed Ecommerce has come to stay.
Prepared by Sir Lexis Oppong
WEB BROWSERS
A web browser is a software designed to and view
web sites. A web browser translates HTML documents
and allows you to view web pages on your computer
screen. Examples of web browsers are Netscape
Navigator, Safari, Opera, Firefox, Google chrome and
internet explorer.
Features of the Internet Web Browser
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FEATURES OF WEB SITE BROWSER
• Title Bar:
The title bar contains the name of the web file you
have loaded, the name of the program used to load it
and the control button.
The title bar
Prepared by Lexis Oppong
• Navigation Bar
The navigation bar allows a user to go back and
forth between web pages already visited. It contains
two buttons forward and back and a downward
pointing arrow, used in a drop down menu of the
pages already visited.
The navigation bar
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• The Address Bar:
The address bar provides the place where we
type a unique address of a page into. After
typing the address, you can either press enter
or the arrow at the end of the bar to go to the
site. The address bar also has reload button
that is used to reload the page for the address
written in the address bar. The last icon on the
bar is the stop button.
Address Bar
Prepared by Sir Lexis Oppong
• Menu Bar
The menu bar contains commands that we issue to the browser.
These commands are grouped under headings such as File,
Edit and Help. Each menu has a drop down list of the individual
commands that can be used.
Menu Bar
• Page Tab
The page tabs in web browsers allows users to view several
different web pages in the same window at the same time.
• Standard Toolbar:
The standard toolbar contains commands that are frequently
used. Such commands include print and save.
The Tools Menu has some special functions such as
Cookie Manager
Image Manager
Password Manager
Window
Help
Prepared by Joachim Konyo
• Content area:
This is the part of the explorer window that shows the content of
the page you have requested. The content page is usually made
up of text, audio and video. The are also special text called
hyperlinks, that allow users to move to other pages on the web
when they are clicked on.
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• Scroll Bar
The scroll bar allows you to scroll up and down through a
particular page to have access to all of its content.
• Refresh or Reload button
It refreshes the currently displayed page with a newer version
of the same page. It is usually when a page is not well
displayed.
• Status Bar
The status bar provides information and
statistics about a particular page that you
have visited.
• The Homepage
The homepage is the page that a user sets in his browser settings
that tells the computer to load that page every time the browser is
opened. The first page you visit when you load a browser may
differ.
Picture of Google Homepage
LAUNCH AND EXIT FROM A WEB PAGE
A web page is a sample text file that contains not only text, but
also a set of HTML tags that describe how text should be
formatted when a browser displays it on a screen
(HTML- HTML stands for Hyper Text Markup Language. A
“markup language” is a computer language that describes how a
page should be formatted) . The tags are simple instructions that
tell the browser to do things like change the font size or colour,
or arrange things in columns.
Launching A Web page
Viewing a web page on the World Wide Web normally begins by
typing the Uniform Resource Locator (URL) or website address
of the page into a web browser or by following a hyperlink to
pages . The web browser then initiate a series of communication
messages, behind the scenes, in order to fetch and display it.
• First, the server- name portion of the URL is resolved into
an IP address using the global, distributed Internet
database known as the Domain Name System or DNS.
This IP address is necessary to contact and send data
packets to the Web server. The browser then requests the
resource by sending an HTTP request to the Web server
at the particular address. Having received the required
file from the Web server, the browser then renders the
page onto the screen as specified by its HTML,
CSS(Cascading Style Sheet) and other Web languages.
Any images and other resources are incorporated to
produce the on - screen Web page that the user sees.
Most Web page will themselves contain Hyperlinks to
other related pages.
STEPS TO LAUNCH A WEB PAGE
Assuming the URL or website address is
http://www.cosmosschool.com/?_alias=home&
1. Launch the web browser you want to use to browse
2. Type the address in the address bar
3. Press ENTER button
Address bar
COSMOS SCHOOL WEBSITE HOME PAGE
• Exiting a web page
Exiting or closing a web page is as simple as closing any other
window. Clicking the close button on the title bar closes an
application.
You can also exit a web page or site by using the File menu on the
Menu bar. Click on the File menu for a drop down sub-menu.
Scroll down the menu until your mouse pointer can rest on Exit.
Click on it to close the window
Some important abbreviations
• TCP/IP: Transmission Control Protocol/Internet
Protocol.
• FTP: File Transfer Protocol
• SMTP: Simple Mail Transfer Protocol.
• HTTP: Hypertext Transfer Protocol.
• HTML: Hypertext Mark-up Language.
Prepared by Joachim Konyo
Advantages and Disadvantages of the Internet
Advantages of the Internet
Communication
The internet has helped us communicate quickly and effectively.
The use of e-mail has cut down considerably on the cost and
time that it takes to send messages across to people. It is even
possible to communicate via audio and video.
Prepared by Joachim Konyo
Education
Schools and institutions are now able to share educational
resources more than ever before. Virtual classrooms and
correspondence courses have allowed for more people to have
access to quality education.
Information
The internet and World Wide Web are full of information. There
are resources on every field available on the internet. This
makes easy to source for information. It saves time as one does
not have to physically move many places to gather data.
Business
Business organizations are benefiting immensely from the
internet. There are now many online shops that sell goods and
services over the internet.
Government
National governments and their dependent agencies are now
able to communicate with their citizens and indeed other
countries about new developments in the country.
Entertainment
Radio and television stations are able to reach their audience all
over the world. Individuals are able to have access to music and
TV shows that are not usually available in their physical location.
Disadvantages of the Internet
Cost
The cost of internet and its facilities is very expensive. This
leads to a situation where those who do not have money, cannot
benefit from the use of the internet.
Fraud
Internet has also brought a new breed of crime. Identity theft is a
situation where some unscrupulous individuals steal the
personal details of unsuspecting people and are able to
impersonate and steal their money.
Virus attacks
Internet connections have allowed for computer viruses and
malware to spread more quickly and easily. Computer virus such
as Trojan horse spreads through the internet.
Misinformation
People upload data and information onto the internet which are
not accurate since no one person owns the internet. Therefore,
not everything you read on the internet is a fact.
Most connections
to the internet are
done through
the use of
computers.
MOBILE DEVICES
Mobile devices such as cell phones, Personal Digital
Assistants(PDAs), handheld game consoles, smart
phones, pagers and LED televisions also use the
internet.
TECHNOLOGIES USED
TECHNOLOGIES TO
ACCESS THE INTERNET
Internet is a network of networks. It is a
huge environment - a collection of
technologies involved in the Internet.
Now, let us see some of the ways to get
connected to the Internet to access its
huge resource areas.
So many technologies are used to access
the Internet. They are:
DIAL-UP CONNECTION
A dial-up connection uses the analog telephone line
for establishing a temporary communication.
Computer’s digital signals must be converted to
analog signals before they are transmitted over
standard telephone lines. This conversion is
performed by a Modem. Modem is a Modulator
Demodulator. It converts computer digital signal into
analog signal which is suitable for the transmission
over a telephone line and vice versa. Both the
sending and the receiving ends of a communication
channel must have a Modem for data transmission to
occur. Using a dial-up line to transmit data is similar
to using the telephone to make a call.
Computer digital signal is a basic signal, which is regulated by
electric current, used for computer communication.
The client computer modem
dials the pre-programmed
phone number for a user’s
Internet Service Provider (ISP)
and connects to one of the
ISP’s modems. After the ISP has
verified the user’s account, a
connection is established and
data can be transmitted. When
either of the modems hangs up,
the communication ends. The
advantage of dial-up line is that
it costs no more than a local
telephone call.
A dial-up connection using a telephone line
A Modem
ISDN
ISDNs (Integrated Services
Digital Networks) are special
digital telephone lines that can
be used to dial into the Internet
speeds ranging from 64 to 128
kbps. These types of
connections are not available
everywhere. Telephone
companies have to install IDSN
digital switching equipment.
IDSNs require the use of a
special “digital modem” that
sends and receives digital
signals over IDSN lines.
ISDN Connection
CABLE MODEM
Currently, most households with
cable TV have the option for cable
modem Internet access. The cable
modem offers a high-speed link at
low cost for unlimited access. The
connection speeds range from 128
Kbps to 10 Mbps (megabytes per
second). A cable modem is a
device that connects to the
existing TV cable feed and to an
Ethernet network card in the
user’s PC (also called an
NIC
– Network Interface Card).
Cable modem
DSL
DSL service is a high-speed data service that
works over POTS (Plain Old Telephone
Service) copper telephone lines and is typically
offered by telephone companies without costly
installation of a higher-grade cable.
ADSL (Asymmetric DSL) is the type of DSL that
provides different bandwidths in the upstream
and downstream directions. SDL (Symmetric
DSL)
offers the same bandwidth capability in both
directions.
DSL modem set up
SATELLITE CONNECTION
Getting the Internet feed from a satellite is not
completely different from getting TV signals from
one. In both cases, data is being sent from the
satellite to a user’s equipment and then translated
and decoded. One major limitation of satellite
technology is that it can only send data from the
satellite to a user’s receiver – not the other way.
To get around this problem, a separate ISP
connection is needed to send data to the Internet,
typically over an analog modem. This connection
works in conjunction with the satellite feed.
Internet via Satellite
TELEPHONE LINE
Modems do not need a
special telephone line;
instead one can use the
regular telephone line
for the Internet.
However, the drawback
of such an arrangement
is that the phone cannot
be used to make or
receive other calls, while
the computer is using it.
Telephone line set up
GPRS
GPRS (General Packet Radio Service)
is a packet based communication
service for mobile devices that allows
data to be sent and received across a
mobile telephone network. GPRS is a
step towards 3G and is often referred
to as 2.5G.
EDGE
EDGE (Enhanced Data rates for GSM
Evolution) is an evolution to the GSM
mobile cellular phone system. The name
Edge STANDS FOR Enhanced Data for
GSM Evolution and it enables data to be
sent over a GSM TDMA system at speeds
up to 384 Kbps. EDGE evolution is
intended to build on the enhancements
provided by the addition of GPRS where
packet switching is applied to a network
Internet Service Provider
An Internet Service Provider (ISP) is a business organization
that provides access to the Internet and related services for
the customer. Speed of an Internet connection can be
divided into two categories: dial-up and broadband. Dial-up
connections require the use of a phone line and usually have
connection speeds 56 Kbps or less. Broadband connections
can be broadband wireless access, cable modem, fiber
optics, satellite or Ethernet. Broadband speed varies
between 64 Kb and 20 Mb per second.
ISPs in Ghana
• There are several ISPs in Ghana. Some of them are as
follows:
• Africa Online Ghana Limited
• Network Computer Systems
• Wireless Ghana
• INTERNET Ghana
• RapidCloud Technology Ltd
• Redline Communications
• NetSAT Ltd
• iBurst
• Broadband4U
• DSL@InternetGHANA
• Zipnet Broadband
• Africanus.net
Internet Service Providers in Ghana
CURRENT TECHNOLOGY
Current Technology in Computer Networks
(A) Wi-Fi
Official Wi-Fi logo
Wi-Fi (wireless fidelity) is a set of standards that refers
to the Wireless Local Area Network (WLAN) that
applies IEEE 802.11 specification.
A computer’s wireless adapter translates data into a
radio signal and transmits it using an 3antenna. A
wireless router receives the signal and 4decodes it. It
sends the information to the internet using a physical,
wired Ethernet connection.
To receive the signal, the router will receive data from
the Internet, translating it into a radio signal and
sending it back to the wireless adapter.
Some of the advantages of using Wi-Fi are as
follows:
1. Simplicity. You can connect computers anywhere in
your home or school without the use for wires.
Computers connected to the network using radio
signals and computers can be up to 30 meters or so
apart.
2. Cost Wireless Networks are easy to set up and are
inexpensive.
3. Easy Access Wi-Fi supports 1roaming by moving your
computers from one access point to another as you
move around a 2hot spot. Wi-Fi works like a two-way
radio communication.
B. Bluetooth
Bluetooth logo
Bluetooth Headset
Bluetooth is a network standard, specifically a protocol that
defines how two Bluetooth devices use short-range radio
waves to transmit data. The data transfers between the
devices at a rate of up to 2 Mbps. To communicate with
each other, Bluetooth devices must be within 10 metres but
can be extended to 100 metres with additional equipment.
A Bluetooth device contains a small chip that allows it
to communicate with another Bluetooth device.
Examples of Bluetooth-enabled devices are desktop
computers, notebook computers, handheld computers,
PDAs, smart phones, headset, microphones, digital
cameras, fax machines and printers.