Transcript Internet and World Wide Web

The Internet is a global network connecting millions
of computers with ability to share resources and to
communicate.
The internet is a computer network consisting of a
worldwide network of computer networks that use
the TCP/IP network protocols to facilitate data
transmission and exchange.
Advantages of using the Internet
• The Internet allows greater communication between all people
throughout the world and breaks down geographical and cultural
boundaries.
• The internet provides entertainment and information for millions of
people through online music and movies.
• The Internet allows people who are otherwise isolated from the
society for whatever reason to interact with the society.
• The Internet provides educational, health and commercial services
to people anywhere in the world.
• The internet is changing the work place environment by allowing
people to work from home and remote locations.
• The Internet provides people with membership to a
worldwide library and resource center.
• The Internet has become the information
superhighway for the buying public with hassle free
transactions that Internet shopping can offer as a
result; the Internet has become the most powerful
selling tool.
• The Internet is a source of employment for those with
skills such as researchers, web site designers and
webmasters.
• The internet offers a wide variety of software
applications that can be downloaded for use for
example games software, device drivers.
Disadvantages of using the internet
• The internet is a big source of pornography and this has led to moral
decay for example lesbianism and homosexuality.
• Because knowledge is power, the internet extends division between
the privileged and the under privileged.
• The security of data belonging to individuals, businesses and
governments may be jeopardized or at risk from unauthorized
access since computer experts can easily access this information.
• The internet enables opportunities for fraud for example illegal
money transfer.
• The internet promotes the spread of computer viruses through junk
(useless) mails and computer games.
• There is no controlling body that verifies the validity of
information or restricts illicit materials.
• The Internet can isolate people from direct social
interaction as well as erode the socio aspect of work.
More and more people are getting engulfed in virtual
world and drifting apart from their friends and family.
• Spamming which involves sending of unsolicited
electronic mails in bulk that serve no purpose and
unnecessarily clog up the entire system. (Spamming
refers to sending unwanted e-mails in bulk, which
provide no purpose and needlessly obstruct the entire
system).
• Computer crimes such as hacking, piracy and
information theft and all these bring more invasion of
privacy of individuals.
• Unemployment as more and more less skilled people
get retrenched and their roles taken up by more
efficient IT experts
• Increased instability in man being all the time insecure
for his future and is compelled to learn new things
every now and then.
• Isolation of the old being hard for them to cope with
the many IT changes.
• IT related health problems like eye strain, repetitive
strain injury.
• Computer addiction by young people like playing
games and over surfing
• Increased installation and maintenance costs
Positive aspects of internet:
• Personal/business connectivity – through E-mail,
chatting, video conferencing, websites News updates
through online news groups and news rooms.
• Secure online data storage.
• Internet based education and research e.g. online
training, publications
• Tool for entertainment and leisure through online games,
music and video clips, visiting of electronic zoos, etc.
• Promotion of business through internet based
trade and commerce
• Promotion of medicine and health through
online medication and health care.
• Promotion of banking and finance through
online banking.
• Widened business investment opportunities and
job opportunities through; IPS’s, internet service
kiosks (café), online jobs, etc.
Negative aspects of internet:
• Very high cost implications for initial capital outlay and maintenance
costs.
• Display of illicit/dangerous (pornographic) materials on grounds of
health and materials.
• Promotion of crime through Hacking, Piracy, and Money laundering.
• Internet as a source of viruses through e-mail attachments, free
games, etc.
• Addiction where people waste a lot of time.
• Loss of man-hours as employees waste company time on
unproductive surfing.
Undesirable behaviours involving the internet
• Spam: Electronic junk mail or junk newsgroup postings.
• Pirating-making illegal copies of genuine software
• Watching immoral websites before you are of age
• Illicit/criminal/illegal material
• Abusive and threatening messages
• Hacking and cracking
• Impersonation
ISP- Internet Service Providers
• ISPs are
organizations/companies
that avail Internet services
to those who need them
and are willing to pay for
them.
Examples of Internet service providers
• Local service providers-MTN, UTL and Airtel, K2, Orange
• AOL and MSN-online service providers
• AT&T world net
• Comp serve interactive
• Microsoft network
• Prodigy Internet
Uses of Internet service
providers
• Provide their users with a mail box which stores their emails on a special server called a mail server
• ISPs provide an address for a specific resource on the
web for example addressing schemes used to link
resources on the web.
• ISPs operate local area networks connected to the World
Wide Web
• ISPs connect organisations and individuals to the web
• ISPs also provide technical support
• ISPs provide local telephone numbers
• ISPs also provide the connection media such
as modems
• Electronic mail services
• Leasing server space for small businesses.
• Web hosting services.
• Provision of virtual machines e.g. storage space
Factors to consider when choosing an
Internet service provider
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Speed
Packages and equipment
Bandwidth of the ISP
Nature of customers
Past experience
Administrative support/budget
Software used
Consultancy from technical specialist in that field
Hard ware and software requirements for
internet use
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Computer
Modem
Telephone line connection
Communication software Browser software. E.g.
Internet explorer or Mozilla Fire fox
An account with an internet service provider
(Register with an ISP (Internet service provider)
Network Interface Card (NIC).
Transmission medium (cables or wireless)
Network operating system (NOS)
Uses of the Internet (Why people connect
to the internet)
• Transfer of research papers, ideas and mails
• Easiest way of availing product information
• Advertising and providing customer support
internationally
• Access a wealth of information, news and research
information
• Communicate with people around the world
• Shop for goods and services
• Down load and listen to music and watch videos
• Access educational materials
• Access entertainment sources
• Access other computers and exchange files
• Provide information, photographs and audio clips.
• Bank and invest
Factors affecting communication speed
over the internet
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Slow transmission time
Malfunctioning web servers
Messed up connection properties
Bad uniform resource locators
Bad connections
Traffic on the internet at any time
Band width
Speed of the internet service provider’s server
Computer processing speed
Capacity of hardware
Location of software and files
Network topology
Ways of connecting to the Internet
• Modem
• Dial-up modems
• Cable modems
• Digital subscriber line (DSL)
• Integrated services digital network (ISDN)
• T-1 LINE (leased line)
a) Modem
• The word modem is an abbreviation of
Modulation DEModulation. Modulation is
to covert digital signals into analog signals.
Demodulation is convert analog signals to
digital signals.
b) Dial-up modems
• A dial-up is temporary connection that uses one or more
analog telephone lines for communications.
• Advantages
• Dial-up modems are cheap and easy to install
• Dial-up modems have a wide technical base because
they have been in use for many years
• Dial-up modems are cheap to maintain
• Disadvantages
• Dial-up modems have limited speed
• Dial-up modems use up the whole telephone line that is
it is not possible to use a modem and a phone line at the
same time.
c) Cable modems
• These offer a means of connecting the computer to the
Internet through a coaxial television cable instead of a
telephone line. This means they offer high speed for
Internet connection and are suitable for home and
business use.
• Advantages
• They are very fast
• They do not use up the entire phone line.
• Suitable for home and business use
• Disadvantages
• They are expensive to buy and install.
• They need extra hard ware, which is an additional cost.
d) Digital subscriber line (DSL)
• This uses standard copper phone lines to transmit data
in a digital form at a very high speed.
• Advantages
• This method is good for private home and small
businesses as well.
• It uses a standard formula
• It does not use up the entire phone line so it can allow
Internet connection and phone calling at the same line.
• Disadvantages
• Requires extra hardware
• Not available with all Internet service providers
e) Integrated services digital
network (ISDN)
• This is an Internet connection that uses a special
telephone line running directly from the hub to the users’
house or business.
• Advantages
• This computer connection is widely supported
• It is faster
• Can support more than one computer
• Does not hold up the entire phone line
• Produce clear voice conversations
• Disadvantages
• It is expensive to set up and maintain
• It requires extra hardware
f) T-1 LINE (leased line)
• It is a high-speed digital connection that avails a
large line and is good for small to medium sized
companies.
• Advantages
• It is very fast
• Offers a broad technical base
• Disadvantages
• It is very expensive
• Requires extra hard ware and services from a
telephone company
World Wide Web (WWW)
• A network of servers linked together allowing
access to millions of hypertext resources.
• WWW consists of a worldwide collection of
electronic documents.
• WWW is a system of internet servers that
supports the hypertext markup language
documents.
• It is important to understand that the Internet is
not the same as the WWW. The WWW is to the
Internet.
The Difference between the
Internet and the World Wide Web
• The internet is a worldwide collection of
networks linked together whereas the WWW
consists of a worldwide collection of electronic
documents each of which is called a webpage.
• The internet connects millions of computers
together globally, forming a network for
computers to communicate with each other
whereas the WWW is an information-sharing
model and is a way of accessing information
over the medium of the Internet.
Web browsers
• A browser is a program used to locate and
display Web pages. These are programs used to
interface between the web and computer users.
These are computer program software that
access web pages and displays them on the
computer screen. These are client programs that
read files from a web server. These are
programs that send requests for information that
is available on the internet and display the
information for the user.
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Examples of web browsers
Internet Explorer (IE)
Mosaic
Netscape navigator
Google chrome
Mozilla Firefox
Opera
• Search engines
• Search engines are software programs used to
find web sites, web pages and files on the
internet. This is a program that searches
documents for specified keywords and returns a
list of the documents where the keywords where
found. A search engine is software that searches
web pages, indices them, identifies web pages
related to key words and topics that you ask for.
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Examples of search engines
Alta vista
Dogpile
Excite
Ask Jeeves
Yahoo
WebCrawler
Google
• Searching the web
• Web server: This refers to the computer
that delivers web pages that you
request for.
• Hyperlink: This is also called a link. It is
a built-in connection to another related
web page or part of a web page.
• A web page is a hypertext document accessible via the
World Wide Web. A web page or webpage is a document
or information resource that is suitable for the world wide
web and can be accessed through a web browser and
displayed on a monitor or mobile device. A web page or
webpage is a document commonly written in hypertext
markup language (html) that is accessible through the
internet or other network using a browser. A web page is
a document on the World Wide Web. Every web page is
identified by a unique URL (uniform resource locator).
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List four qualities of a good web page
‹ Should load quickly
‹ Should have feedbacks
‹ Should have links to other resources
‹ Should have date of last update
‹ Should have good navigation buttons
‹ Should have a web page title and brief
summary about the page
• Why is it not good to have a lot of graphics on a web
page?
• ‹ It may take long to load.
• ‹ Client computers may support different colour depths.
• ‹ Graphics take a lot of space.
• Describe how a web page is a source of information
• ‹ Research making
• ‹ Educational material- online learning
• ‹ Advertisement
• ‹ Entertainment
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List four qualities of a good web page
‹ Precious content
‹ Use minimal graphical effects
‹ Consumer requirements
‹ Copyright considerations
‹ Avoid use of frames
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State five advantages of web publishing
‹ Easy access to information
‹ Access to market 24 hours a day
‹ Faster communication among individuals
‹ Saves money for paper and printing
‹ Bigger audience
‹ Convenient support to customers
‹ Contents can be updated whenever changes
have been made.
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Explain why a school should have a web page
‹ Present information of interest
‹ Share knowledge and information
‹ Enhance skill building like writing, editing
‹ Provide motivation
‹ Encourage pride of ownership
‹ Enhance communication and collaboration
• A website is a location connected to the Internet
that maintains one or more web pages on the
World Wide Web. A website is a collection of
web pages (documents that are accessed
through the Internet). A website is a collection of
related web pages served from a single web
domain. A webpage is a document that uses
http on the website covering a particular
topic/related topics. A website is a collection of
related web pages or World Wide Web pages
maintained by an organization or an individual.
Types of websites
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News websites:
Informational websites:
Business/marketing websites
Wikis
Online social networks
Educational websites:
Blog
Media sharing website
Web portal
Content aggregator
Wikis
Media Uploading Sites
Social Networks
• News websites:
• These websites provide up to date
information about what is happening in the
world. Examples include new vision, CNN,
BBC and Bukedde.
• Informational websites:
• These websites have updated information
on the on a variety of fields and facts.
• Business/marketing websites
• may have a catalogue that may include all
the goods that you have in your company,
contact address so that in case people
want the goods they may be able to know
how to get to you, background information
of your business and mode of payment
that is how your goods can be purchased
and the shipping details.
• Wikis
• A wiki is a website whose users can add, modify,
or delete its content via a web browser using a
simplified markup language or a rich-text editor.
Wikis may serve many different purposes, such
as knowledge management and note taking. (An
example is Wikipedia,
• WikiHow, and Wikia) A Wiki is a site where users
collaboratively edit its content.
• Online social networks
• These are web sites that focus on facilitating the
building of social relations among people who,
for example, share interests, activities,
backgrounds, or real-life connections. Social
networking sites allow users to share ideas,
activities, events, and interests within their
individual networks. (Examples include Face
book, Twitter). These are sites where users
could communicate with one another and share
media, such as pictures, videos, music, blogs,
etc. with other users.
• Educational websites:
• These are websites that have a lot of
scholarly materials these may include
online library, journals, educational articles
and books too. Any topic of interest can be
searched through this engine.
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Blog
A blog is a discussion or informational site published on the web and
consisting of discrete entries (posts) typically displayed in reverse
chronological order (the most recent post appears first). Short for Web log,
a blog is a Web page that serves as a publicly accessible personal journal
for an individual. Typically updated daily, blogs often reflect the personality
of the author. A blog is a website where someone (usually a normal person not a professional writer) writes about a topic. Blogs can be personal
(someone writing about their own life, or their personal views), based on an
interest (e.g. football), or some businesses also use blogs to write about
new products, etc. A blog allows someone to be a writer and publisher on
the Web with very little effort or cost. A blog can be setup with just a few
clicks, whereas a few years ago you'd need a lot of technical knowledge to
create your own website. Many blogs have systems that allow readers to
leave comments and begin discussions connected with the blog posts.
Blogs allow people to publish their views and opinions very easily, without
anyone else checking what they are writing.
• Media sharing website
• Media sharing sites allow you to upload your
photos, videos and audio to a website that can
be accessed from anywhere in the world. You
can then share that media with the world or just
a select group of friends. A Media sharing Web
site that enables users to store and share their
multimedia files (photos, videos, music) with
others. The media is played/viewed from any
Web browser and may be selectively available
via password or to the general public. A media
sharing site can also be used to back up files.
• Aggregator refers to a web site or computer
software that aggregates a specific type of
information from multiple online sources. A
content aggregator is an individual or
organization that gathers Web content (and/or
sometimes applications) from different online
sources for reuse or resale. There are two kinds
of content aggregators: (1) those who simply
gather material from various sources for their
Web sites, and (2) those who gather and
distribute content to suit their customer's needs.
• Web portal
• A web portal is a website that brings information
together from diverse sources in a uniform way.
A Web portal or public portal refers to a Web site
or service that offers a broad array of resources
and services, such as e-mail, forums, search
engines, and online shopping malls. The first
Web portals were online services, such as AOL,
that provided access to the Web, but by now
most of the traditional search engines have
transformed themselves into Web portals to
attract and keep a larger audience.
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Media Uploading Sites
There are many websites that allow users to create, upload and share their
own media such as photos, music or video. Usually other users can rate
or comment on the media that is uploaded leading to these sites often
being referred to as 'Social Media' sites. All media upload sites have rules
about the type of media that you can upload - you have to either own the
copyright to the image / music / video yourself, or have permission from
the copyright owner. The most famous video upload site is YouTube. Video
upload sites are especially popular. However the videos that are uploaded
can sometimes contain offensive scenes (this is why YouTube is blocked in
so many schools).
Some popular media upload sites:
YouTube (video)
Vimeo (video)
Flickr (photos)
PhotoBucket (photos)
MySpace (music)
ccMixter (music)
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Social Networks
A social network website is a site that allows user to connect with other
users who are friends /relatives, or who share similar interests. Connected
users can then share information / pictures / files with each other, send
messages, chat, etc.
One of the biggest social networking websites is Facebook
For many people, social networking sites are the main method of
communicating with friends online. In fact social networks have surpassed
e-mail as the main communication link for non-business Web users.
Bebo
Friendster
Habbo
LinkedIn
MySpace
Orkut
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Advantages of social networking
It is usually free
Very easy to keep in contact with people of similar interests
Very easy to contact potential new friends
The site makes it simpler to get in touch with long-lost friends
You can post interesting things about yourself and your achievements online.
Disadvantages of social networks
You lose some privacy compared to not being on a social network
You may later regret posting pictures or comments that you thought funny at the time
Online bullying can be a problem if someone posts unkind or untrue things about you
Some people may use a fake profile - just because they say they are 15 years old
does not mean that is true. Be careful when you choose to be friends with someone
you have never met in real life
They can be a real distraction and time waster, some people spend many hours on
social networking rather than be working or studying. For example, constantly
checking their twitter feeds. Take everything you see with a pinch of salt - people do
like to boast and exaggerate (just like they do in real life!)
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Cloud computing
Cloud computing is a type of computing that relies on sharing computing
resources rather than having local servers or personal devices to handle
applications. In cloud computing, the word cloud (also phrased as "the
cloud") is used as a metaphor for "the Internet," so the phrase cloud
computing means "a type of Internet-based computing," where different
services -- such as servers, storage and applications -- are delivered to an
organization's computers and devices through the Internet. Cloud
computing refers to the use and access of multiple server-based
computational resources via a digital network. Cloud users may access the
server resources using a computer, notebook, smart phone or other
devices.
In cloud computing, applications are provided and managed by the cloud
server and data is stored remotely in the cloud configuration. Users do not
download and install applications on their own devices or computers; all
processing and storage is maintained by the cloud server.
• Risks exposed to cloud computing users
• Exposing the user to potential violation of privacy
• Freely collecting public data and privately storing it on
the cloud’s archives. No guarantee is given to the users
for free future access.
• A malfunction can affect a larger number of users at
once because these services are often shared on a large
network.
• There is no defined standard between the operators and
any change is extremely complex therefore there are
data migration problems when changing the cloud
provider.
• Advantages of cloud computing
• Cloud computing is probably the most cost effective method to use,
maintain and upgrade information systems.
• Almost unlimited storage for information in the cloud gives you
unlimited storage capacity.
• Because all the data is stored in the cloud, backing it up and
restoring the same is relatively much easier that storing the same on
a physical device.
• Software integration is usually something that occurs automatically
so you do not need to take additional efforts to customize your
applications.
• Once you register yourself in the cloud, you can access the
information from anywhere where there is an internet connection.
• Cloud computing is easily scalable so companies can add or
subtract resources based on their needs.
• Disadvantages of cloud computing
• Storing information on the cloud can render the data and
information vulnerable to external hack attacks and
threats.
• Long term dependency on the cloud host for
maintenance of your information is another short coming
of cloud computing.
• Dependency on the third party to ensure confidentiality
of data and information is another limitation of cloud
computing.
• There is less control that comes when handing over all
your data and information to the cloud providers.
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Getting information on the World Wide Web (client server computing)
The internet is a network designed around client server architecture. When
we are surfing the internet using a web browser, we are a client, the
computers that have the information are the servers called web servers.
Servers and clients
Server
This is a computer that responds to requests for information for example an
e-mail server responds to requests to send and receive e-mail messages. It
is a computer that manages resources on the network and provides a
centralised storage area for resources for example programs and data.
Client
This is a computer that requests for information from a server. Client-server
computing refers to the way in which computers exchange information by
sending it as servers and receiving it as clients. Computers devoted to
serving web pages are called web servers.
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URL-uniform resource locator
A URL is the address of a resource on the Internet. The Uniform Resource
Locator is the address of a resource available on the Internet for example
http://www.lib.latrobe.edu.au
A URL is an address that specifies the location of a file on the Internet (e.g.
http://library.wur.nl/). A Uniform Resource Locator is the global address of
documents and other resources on the World Wide Web.
Resources could be:
Text
Graphics
Sounds
Movies
Animations
Application software
• Parts of a uniform resource locator
• Once you enter the URL
"http://www.webopedia.com/browser.html" into your address line,
the browser breaks that Web address down into three distinct parts.
The Protocol: "http" The server name: www.webopedia.com The
file name, which follows the server name: "browser.html" IP
address-Internet protocol address.
• An IP address is a number that uniquely identifies each computer or
device connected to the computer network or data link.
• For example, the domain name www.example.commight translate
to 198.105.232.4.
• Examples of uniform resource locators
• http://www.cnn.com
• http://www.yahoo.com
• http://www.microsoft.com
• ftp://eds.ipi.arizona.com
• Domain name
• The Domain name is the text version of an internet
protocol address. For example, the domain name
www.example.commight translate to 198.105.232.4.
• Domain name system (DNS)
• The Domain name system is a system that permits use
of alphabetic characters instead of numbers for easy
remembrance of the Internet protocol address. The
Domain name system is a system that translates a
uniform resource locator address that you type into a
series of numbers. The computer uses the numbers to
find websites you want to reach.
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INTERNET SERVICES
Retrieval services
a) FTP-File Transfer Protocol
b) Gopher
Multimedia services
c) WWW(WorldWideWeb/W3/Web)
Search services
d)WAIS-Wide Area Information Server
e) Veronica- Very Easy Rodent Oriented Net-wide Index to Computerized Archives
f) Archie
Communication services
g) E-Mail (electronic mail)
h) Telnet
i) Usenet (users’ net)/news groups
j) IRC- Internet Relay Chats (chat rooms)
k) Instant messaging
L) Video conferencing
m) Internet telephony (voice over internet protocol)
n) Voice mail
o) Mailing lists
p) Message boards
• a) FTP-File Transfer Protocol
• File Transfer Protocol makes it possible to send
data contained in files between computers. This
allows users to upload and download files with
other computers. FTP server is a computer that
allows users to upload and download files using
FTP. FTP site is a collection of files that reside
on an FTP server. Downloading refers to
retrieving of files from another computer and
storing the files in your computer on a network.
Uploading refers to sending files from your
computer to another computer on a network.
• b) Gopher
• A hierarchical system for finding and retrieving
information from the Internet or and intranet Is a
menu-based system for exploring the Internet.
Users locate resources by selecting resources
from menus. A system allowing users to search
for files via menus or directory structures. Is a
menu-driven information system that
transparently connects users to other Internet
sites.
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c) WWW(WorldWideWeb/W3/Web)
A network of servers linked together allowing access to millions of hypertext
resources. This consists of a worldwide collection of electronic documents.
This is a system of internet servers that support the hypertext markup
language documents.
It is the most popular service on the internet because of the following
reasons:
It is simple to navigate
It contains millions of documents that contain several media like graphics,
sound, video and pictures.
It presents a wealth of vibrant and interesting information on a variety of
useful, entertaining and useless topics in any attractive way.
The Difference between the Internet and the World Wide Web
The internet connects millions of computers together globally, forming a
network for computers to communicate with each other whereas the WWW
is an information-sharing model and is a way of accessing information over
the medium of the Internet.
• d)WAIS-Wide Area Information Server
• This is a program for finding documents on
the Internet. This is an internet search
service that locates documents containing
a keyword or phrase. This is a set of fulltext databases containing information on
hundreds of topics.
• e) Veronica- Very Easy Rodent Oriented Netwide Index to Computerized Archives
• This is an Internet tool that allows you to search
by keyword through gopher titles and directories.
This is a search utility that helps find information
on gopher servers. Veronica allows users to
enter keywords to locate the gopher site holding
the desired information.
• f) Archie
• A tool used for searching FTP sites for
various program files. Archie is a Netbased service that allows you to locate
files that can be downloaded via FTP. This
is a program that enables you to search
for files anywhere on the Internet by
filename.
• g) E-Mail (electronic mail)
• This is a service that allows a computer user to
exchange messages with other computer users (or
groups of users) via a network. This is a service for the
transmission of messages over networks. This service
enables the transfer of electronic messages from one
geographical location to another using computers and
related computer devices.
• Sending and receiving electronic mails
• Electronic mails involve transmission of electronic
messages and files via a computer network or data link.
• Electronic mail systems use some
standardized application packages like:
• Lotus domino
• Lotus CC: mail server
• Eudora pro
• Quick mail office
• Microsoft outlook
• Pegasus
• Turnpike
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Creating a new electronic mail message
The main components of an electronic mail message are:
The address
Actual electronic mail messages are needed for people outside your organization or
school network. The mail must be addressed to the person who is to receive it. An
accurate address is a necessity for each person who is to receive the message. An
example of an electronic mail address is [email protected]
The subject
The subject should let the receiver know what the message is about.
The message/body
This is where the actual message is entered. You can generally enter as much text as
you need here.
CC carbon copy
This enables one to forward a copy of your message to the user you include.
BCC blank carbon copy
This allows one to send a copy of a message to someone else without the original
recipient knowing.
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Electronic message etiquette
Do not access or disclose other people’s e-mail without prior consent.
Always read the message before sending to check for spelling and grammar errors.
Do not use all capitals when typing since it is difficult to read and is sometimes
termed as shouting.
Keep your message brief for easy reading and understanding by your recipients.
Avoid long paragraphs and use white space to make the message easier to read.
Have an appropriate subject as this encourages the recipient to open and read the
message and also make it easier to find again.
Limit your topics to one subject per electronic mail.
Do not Spam that is mass electronic mailing for the purpose of advertising.
Do not forward angry messages
Do not repeat the entire message to which you are responding.
Read your mails on a daily basis so as to respond to your recipients when it is still
appropriate.
• Replying to a message
• Messages you receive are listed in your inbox. Replying to a person
who sent you an electronic message is very easy. Instead of
creating a new message from scratch, simply open or highlight the
message in the list of messages in your inbox then click on the reply
button.
• Attachments
• Files are attached to electronic messages very easily. A paper clip
icon is commonly used in most electronic mail programs. An
attachment therefore is a file sent along with an electronic mail
message.
• Dealing with unwanted electronic mails
• Just delete them
• Send a reply to show your displeasure
• Use mail filters to always block mail from electronic addresses that
you forbid.
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Advantages of electronic mails
One can send any size of messages just at the cost of a local call.
They can be sent at any time and the results are almost simultaneous because the messages
reach their destinations after a short time.
Electronic mails are highly efficient.
They save a lot of time for example you can present a report at a conference by going to it and
downloading it from the conference.
Saves time, paper, and money compared to the telephone or written letters
The recipient may read the message anytime
Allows you to communicate easily with many people at once
Allows you to thoughtfully compose what you would like to say
Ability to send to multiple recipients at the same time.
It is very easy to send a reply to an e-mail as soon as it is received by using a reply button.
Large files such as spreadsheets and graphics can be sent as attachments
Can be used for advertisements
Assurance of whether the mail has been delivered is given
No use of stamps
Convenient when retrieving and delivering
• Disadvantages
• They cannot be accessed from anywhere
especially when there is no Internet or network
connection.
• Emotion or complete meaning may be lost
without verbal or visual clues
• Cannot be canceled once it has been sent
• Unsolicited or unwanted messages (Spam) may
flood your mailbox
• Keeps a semi-permanent record of the message
h) Telnet
• Telnet is a service used to gain access to a remote
computer. Is a service for logging onto remote computers
from anywhere on the network or data link.
• This is a service that enables one computer to establish
a connection to another computer on a data link.
• Local computer and remote computer
• A local computer is the computer establishing the
connection whereas a remote computer is the computer
accepting the connection.
• i) Usenet (users’ net)/news groups
• This is an electronic message center that can be
accessed through the Internet. Usenet is a world-wide
network of discussion groups (or news groups). It refers
to discussion groups that are continuous as people
share, read, and reply to messages from each other.
• News groups are online areas where users conduct
written discussions about a particular subject. News
groups are topic specific forums where people can post
questions, news, comments or read and respond to such
postings left by other users on the internet or other forms
of the websites.
• j) IRC- Internet Relay Chats (chat rooms)
• This is an internet service that allows you to have real time
conversations with other people over your computer. It is the
Internet’s version of phone calls except that the conversation is
typed. IRC has become very popular as more people get connected
to the Internet because it enables people connected anywhere on
the Internet to join in live discussions.
• A chat room is a location on an internet server that permits users to
chat with others by typing lines of text on the computer. One person
types a message on his/her keyboard and people with whom he/she
is chatting see the message appear on their screens and can
respond almost immediately. Chat rooms permit simultaneous text
communication between two or more people via the computers.
• k) Instant messaging
• This is a real time internet communication
service that notifies you when one or more
people are online and then allows you to
exchange messages or files. IM is a real
time messaging service on the internet.
• L) Video conferencing
• Video-conferencing refers to real time meeting between
two or more geographically separated people who use a
network to transmit audio and video data.
• Video-conferencing is a system that allows people to
have conversations and meetings with other people in
different locations, but without leaving their office.
• A video-conference involves people sitting in front of a
camera and a microphone, whilst watching other
people of a screen and listening to them through
loudspeakers.
• The system uses the following
hardware:
• Video camera
• Monitor
• Microphone
• Loudspeakers
• High-speed network / Internet connection
• Video conferencing is very popular with
businesses as it means:
• No travel costs
• No time wasted travelling to other cities /
countries
• Can organise meetings at short notice
• However there are some problems with video
conferencing:
• Less personal than face-to-face meetings
• Documents (e.g. contracts) cannot be signed
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m) Internet telephony (voice over internet protocol)
This enables users to talk to other users over the internet. Internet
telephony uses the internet to connect a calling party and one or more
called parties.
VOIP is a web-based telephone service that allows the user to talk to
others.
VOIP systems have a number of advantages over a normal telephone
system:
No telephone line is required
Call costs are very low, especially for long-distance calls
Can include video
VOIP systems also have some disadvantages:
Require special hardware and an Internet connection
Not as reliable as normal phones, so cannot be relied upon for emergency
calls
Call quality depends on the speed of the Internet connection
• n) Voice mail
• This allows someone to leave a voice message for one or more
people.
• o) Mailing lists
• A mailing list is a group of electronic mail names and addresses
given a single name. When a message is sent to a mailing list, every
person on the list will receive a copy of the message.
• p) Message boards
• Message boards are also called discussion boards. Messaging
boards are an online service that enables users to post and read
messages with one another.
• Messaging boards are a web based type of discussion groups and
don’t require a news reader program.
• Protocols used for the internet
• Protocols refer to a uniform set of rules that enable two
devices to connect and transmit data to one another.
Protocols determine how data are transmitted between
computing devices and over networks.
• IP- Internet Protocol
• TCP-transmission control protocol
• HTTP-hypertext transfer protocol
• TELNET
• IPX- Inter-networked Packet Exchange
• SPX- Sequenced packet exchange protocol
• Asynchronous Transfer Mode (ATM)
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IP- Internet Protocol
IP enables a data packet to travel multiple networks on the way to its final
destination.
IP is the protocol that is used to route a data packet from its source to its
destination over a data link or network and specifies the format of packets
and the addressing scheme.
TCP-transmission control protocol
A protocol used along with the Internet Protocol (IP) to send data in the form
of individual units (called packets) between computers over the Internet.
Whereas IP handles the actual delivery of the data, TCP keeps track of
the packets that a message is divided into for efficient routing through
the Internet.
TCP is a connection-based protocol, responsible for breaking data into
packets, which the
IP protocol sends over the network. TCP is a protocol that governs the way
data is transmitted across networks.
TCP protocol breaks data into packets, provides routing information for
message delivery and reassembles messages at the receiving end.
• HTTP-hypertext transfer protocol
• HTTP is the protocol for exchanging files (text, graphic
images, sound, video, and other multimedia files) on the
World Wide Web.
• HTTP is a protocol that performs the request and
retrieval functions of a server. HTTP is the Internet
protocol that is used by the server and your computer to
transfer the data between them.
• TELNET
• This is a protocol used to logon to a remote computer.
• IPX- Inter-networked Packet Exchange
• This is a communications protocol used to move data
between server and/or workstation programs running on
different network nodes.
• SPX- Sequenced packet exchange protocol
• This protocol provides a method for two workstations or
applications to communicate across the network.
• Asynchronous Transfer Mode (ATM)
• This is a protocol in which a logical connection is
established between the two endpoints before the actual
data exchange begins.
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Information sharing methods
IMAP-internet message access protocol
This is a protocol that is used to receive electronic mail messages over the
Internet.
LDAP-light weight directory access protocol
This allows you to search for electronic mail addresses and other contact
information on the Internet.
POP3-post office protocol version 3
This is used to receive electronic mail messages over the Internet.
NNTP-network news transfer protocol
This lets you receive more news group messages to and from news
servers.
SMTP-simple mail transfer protocol
This allows you to send electronic mails over the Internet.
PPP-point to point tunneling protocol
This enables Internet users to connect to private networks.
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Internet etiquette/netiquette
Internet etiquette/netiquette refers to the code of conduct to follow while on the
Internet.
Some of the rules include:
Think about the social consequences of the program you are writing or the system
you are designing.
Remember that any one on the Internet can read your posting.
Be forging
Do not hide your identity
Avoid entering into stupid arguments over stupid ideas.
Do not forward chain letters
Never send unsolicited junk mails
Respond to your recipients and do not waste people’s time for long private
messages.
Respect your audience and do not waste people’s time with idle nonsense.
Being online does not mean or turn you less than what you are.
Never do anything online that you could not do in real life.
Keep messages and postings, remarks short and relevant to the current subject.
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Electronic commerce/electronic business
Electronic Commerce refers to the buying and selling of goods and services over
electronic systems such as the Internet and other computer networks.
Electronic Commerce refers to the buying and selling of goods and services over
electronic systems such as the Internet and other computer networks.
Advantages of electronic commerce
Access to the global market 24 hours a day.
Access to many people
Consumers conduct price comparisons easily.
Feedback can be immediate
Changing information can be available quickly
FAQ pages can provide easy access to consumer support.
Ability to gather customer information, analyze and react.
New approaches to generating revenue.
Manufacturers buy and sell directly hence avoiding cost of middlemen
Reduced costs for distributing information.
Options to creating a paperless environment.
Disadvantages of electronic
commerce