Chapter 7

INTERNET, ECOMMERCE & EMAIL

Network
A network is a group of connected computers that allow people to share information &
expensive equipment such as printers. They are classified according to the size of the area
they span

Types of network
1. Local Area Network (LAN)
LAN is a network that connect computers within a small geographical area e.g. building
2. Wide Area Network (WAN)
Connect computers across a large geographical area such as a city or a country
Wan transmit information through micro waves or satellites

Parts of a Network
Before you are able to get the facilities that the network offers the following components must
be in place:-
1. Cables
Used to connect the computers and the equipments to a network

Types of cables
a) Coaxial cables
b) Unshielded twisted pairs
c) Shielded twisted pairs
d) Fibre optics (most expensive cables for they can transmit faster for longer
distances)

2. Network interface card

It’s a card that physically connects each computer to a network
It control the flow of information between the network and the computer
It’s usually found on the computers mother board
The cables are connected to it from the rea - visible end of the card

3. Hub
Provides central location where all the cables of the network come together

4. Network traffic
This is the information that travels through a network when there is a lot of network traffic the
information travel more slowly through the network

How information is stored in a network

When computing, information generated has to be stored for future reference. This
information can be stored on any other computer as follows

Peer to peer
All the people in this kind environment store their files in their own computers
Any one on the computer can access file stored in any other computer on the network
Files are stored in many different locations making it different to manage back ups and
protect, however if one computer malfunction the rest of the computer in the network will not
be affected.

Client server
All the people in the client/server environment store their files in a central computer
A sever is a central computer that stores all the files in the network
A client is a computer that can access information stored in the server
Exchange of information
The main purpose of a network is to share information and resources
For these and others to happen data has to be transformed from one end to the other
There are three common mode of data exchange
a) Ethernet
b) Token ring
c) Asynchronous transfer
The mode of exchange is hardware dependent

Ethernet
It’s the easiest type of network to set up
It work the same way people talk during a conversation
Each computer waits for pause before sending information through a network
When two computers try to send information at the same time, collusion occurs after a
moment the computer resend the information.

Token ring
Often found in large organizations
It works by passing a single token from one computer to another.
The token collects and delivers information as it travels through the network.

Asynchronous transfer mode

This is a newer more powerful more expensive way of exchange.
Today many companies use ATM to transfer information between separate networks
information between separate networks
It works by sending information in equal sized pieces called fixed packets

Types of security in a network

1. Fire wall
This is a special software or hardware designed to protect a private computer from
unauthorized access
Corporations, banks and such facilities use firewalls

2. Username & Passwords

To access information and other resources in the internet a password and a usernames are
required, this is to ensure that only authorized people can access information stored in the
network.
Advantages of a network
a) Sharing of information
b) Sharing of expensive equipments and resources e.g. printers and modems
c) Its easy to connect to a network from anywhere
d) It eliminates physical carrying of information from one computer to the other and
from one place to another

INTERNET
It’s a world wide network connecting millions of computers around the world
It is an interconnection of personal computers throughout the world through ordinary
telecommunication lines and modems.
Other names
 The Net
 Information superhighway
 Cyberspace
Facilities offered by the net
1. Electronic mail-For sending and receiving Emails
2. Information e.g. newspapers and academic papers
3. programs e.g. word processor spread sheet games et c
4. entertainment e.g. games movies music etc
5. chatting or discussing groups – people from around the world with similar interest
can solve problems and share ideas and ask questions

E commerce
Its online shopping
You can order goods & services throu the internet with out leaving you desk. Just leave a
catalogue on line
This facility can be used as tool in various always:-
1. As a research to
2. Advertising or trading to

Uses of the Internet

 Researcher can get information
 Individual can use it for their work to communicate
 People with the same interest can share ideas
 Large orgs can communicate with subsidiary co. Or their supplier
 Student and school children can communicate and gather information
 Business men can advert, communicate and sell goods
 Buyers can shop on line

Facilities Needed
1. A Computer
There are several elements that are desirable in a computer
a) Fast processor so as to quickly access and down load information and program from
the internet
b) A color screen to view the various graphics and images
c) Free disk space in which to load the program and information from the internet

2. Web Browser
These are spaced program needed for the computer to access the net
These programs include: - the web browser used to view and explore information e.g.
Netscape navigator or Ms Internet explore.

3. Modem (Modulator, Demodulator)

This is a device that enables the user connect to the internet and access information as a
transmitting modem it translate computer information in to a form that can be transmitted
over telephone lines (modulates) digital to analogue. As a receiving modem it translate
information in to a form that a computer can understand (demodulate) analogue digital

A fast modems essential, it will reduce the time spurn waiting for files messages or
communications from the internet.
Modems speeds are quoted in BPS (Bits per Second). Typical speeds are 9600BPS, 44KBPS,
28.8KBPS, 50KBPS e.t.c
.
4. Internet Service Providers (ISP)
This is a commercial organization that provides access to the internet along with a set of
support services for a fee.
5. Username
Every time persons corrected he needs a name to identify himself in the internet. This is done
when the user registers with the ISPs.

6. Password
This is needed for security purposes; you need to enter the user’s name, the password when
you need to access the internet.

Connecting or logging to the internet

The purpose is to be able to gain access to the facilities offered by the net. You can do this by
starting web browser by double clicking on it.
Upon successful logging on, the home page is displayed.

The Web
WWW (World Wide Web). It’s a part of the internet that consists of a huge connection of
document stored in computers called hosts around the world.

NB/ A host computer is any computer connected to the internet and have stored information
that a user has made available to the web.
The web allows the user to browse the internet. You can view a document in a different
computer by typing the address that identifies the location of the computer.
To browse any information in the web one uses a browser.

Web Browsers
It’s a program that lets the user explore, browse or surf information from the web.
Information on the web is structured into pages. Each page has a specific address that is used
to locate and access information on that page.
Two browsers that are in the market are:-
1. The Ms Internet Explorer
2. Nets page navigator

Web Page
It’s a document on the web. Web pages include texts, pictures.

Home page
It’s the page that appears each time you access the web.

Website
It’s a collection of web pages maintained by an organization or individual.

Web Address (Uniform Resources Locator (URL).

Each web page has a unique address or location. You can instantly display any web page if
you know its URL e.g. HTTP:\ WWW.COMPAQ.COM.
Hyperlinks
Links one web page to another by use of some phrases or words underlined different from the
rest and when clicked, it opens another website.

HISTORY
Keeps track of all the pages that have been opened since the web browser started

Viewing Connecting Information

When one registers with ISP this is called having an account with an ISP.

Logging Out or Disconnecting

When connected you continue to incur telephone and internet charges to avoid this you have
to log out when you finish.
Procedure:
1. Position the pointer on the connection pointer on the desktop.
2. Right click on it.
3. Then click on disconnection it will automatically disconnect.

E-MAIL
This is a world wide system for sending and receiving electronic messages from one
computer to another. E-Mail is faster, economical and convenient.
Signing in
Reading E-Mail Messages
1. Log – in to the internet through the ISP if not already online.
2. Click on the mail button in order to launch the E-mail program.
3. From the dropdown list click on read mail.
4. Choose the profile; a dialogue box appears to allow you to access the program you
have installed for sending mail then click ok.

5. The inbox is where all incoming messages are stored when you connect to outlook; it
displays all the e – mails you’ve received.
6. To open and read E-mail messages in the inbox, click on the inbox icon and choose
the message that you want to read. Double click on it to open.

Compose
It involves: -
1. A computer where you’ll send or receive E-mail messages.
2. Your E-mail address and that of the receiver
3. Internet service provider (ISP).
4. An E-mail program that let’s you send, receive and manage your E – mail messages
Attaching Files to an E-Mail Message
Click on new message button, the message composition dialogue box appears. Enter the E –
mail address and the message to be sent.
To attach a file click on attach files
The attach dialogue box appears locate the file to attach, select it and click o.k. or double
click on it.
The attachment will appear as on icon on the body of the message click on send button.

To Open or View the Attachment

You must have the application in which the attachment was composed in order to open it.
In the dialogue box select the message which contains the attachment, Double click on it to
open, Double click the icon which represents the attachment.

Sending a Web Page by E-Mail

Access the web page you want to send.
On the file menu, select send and click page by E – mail.
Choose the right profile to use from profile dialogue box to Ms Outlook and click o.k.

Viewing Information from the Internet Offline

This is done to cut off time thus cost.
Procedure
Download all the information you require their right click on the connection indicator then
click on the connection indicator then click on disconnect.

Setting a Home Page

Make sure that you access the page or write down the address of the website to set as a home
page click on tools then click on address at the homepage section and type the address of the
new homepage in the dialogue box and click o.k.
Search engine.
They are important when you want to get information about an area or subject of interest and
you don’t know where to find it.
You can use search tools to locate it.
A search engine is software that quickly helps you to locate information on the web. There are
several search engines e.g. Yahoo, Information sake, Lycos Web Controller, Excite.

Procedure
1. Select a search engine and type its address.
2. Type the key word in the search box and click search to start finding. Its steps will
vary depending on the search engine you’ve using. When the search is completed,
you get on list of websites that contain the key word you’re looking for choose the
one which looks closest.
3. If there are very many sites not all will be displayed, However there’ll be an option
allowing you to view 10 or 50 matches then click on this if necessary.
4. If there are too many matches you need to use an addition key word to narrow down
the search. Type the additional keyword in the search box e.g. Kenya + Economy to
narrow down to sites that contain information about the economy of Kenya.

Favourites or Bookmarks
When you browse on the web you may come across sites that you’ll wait to visit regularly
The bookmark feature (favorite) lets you store the addresses of web pages that you don’t have
to remember and constantly type your favorite web page address.
When you want to visit the website you simply select the book mark from the list.
Procedure
1. Open or visit the website that you want to create a bookmark to
2. Select the favorites from the menu bar, choose add favorites and click o.k.
3. Once you do that title of the website will be added as part of the favorite menu.
To Get to a Site Using a Bookmark
1. Click on start
2. Then point to favorites and click on the site address.

Printing Web Pages

The Purpose
To obtain a hard copy of the information that you’re searching for, for the purpose of
reviewing later
Procedure
1. Click on file, point to print and click.
2. The print dialogue box appears
3. Upon selecting the pages you want to print click o.k.
 Com – commercial
 Org - large organization
 Gov - government
 Edu - education.