Download Unit3AlexaICT - i

Unit 3: Communications, Networks
and Internet
Alexa C.
Year 10
Communication
 Communication has revolutionized the way that businesses
work and has enhanced everyday life.
Communication Methods

1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
Ways we communicate:
Telephone
E-mail
Gas flare
Morse Code
Talking drum
Sonar signals
Twitter
Facebook
Letter writing
Sign Language
Video conferencing
Instant Messenger
Internet
Facial expressions
Bird messenger
Lip reading
18.
Brail
Talking
19.
Fax machine
17.
Networks
 A network is a group of two or more computers linked
together so that they can share resources (hardware, software
and data) and can communicate with one another. A
standalone computer is a computer not connected to a
network.
 By joining computers together to form a network, they are
able to share a printer. This means that more money can be
spent buying a better quality printer and the printer is being
used much more of the time.
 A computer connected to a network is known as a ‘workstation’
Networks
 In my own words: a network is the connection of electronic
devices enabling them to share hardware, software and data.
Types of Computer Network:
 Local area network (LAN)
 Wide area network (WAN)
 The Internet
 Extranet
 Intranet
 VPN (Virtual Private Network)
Local area networks (LAN)
 A LAN consists of a collection of computers that can share
peripherals, share information and communicate with each
other over a network these computers are likely to be in the
same building, area or room.
 Within a workspace you can have different LANs. Our school
consists of a LAN that allows us to access information from
the network server. In addition, our computers can also work
independently.
 For a work-station to share information it must have access to
a server. A server is a powerful computer that runs the
network operating system and allows resources to be shared
over the network by other devices.
Wide area network (WANs)
 A WAN can connect to networks across a large geographical
area. E.g. a city or country.
 Information can be transmitted in various ways: using highspeed telephone lines, fiber optic cables, microwave links and
satellite links.
 Mainly used by large companies, universities, and banks with
branches in different countries.
Components of a WAN
 Modem – stands for modulator demodulator
 It is a device used to convert the digital signals emitted by the
computer into analogue signals that can be transmitted over a
telephone line.
 Speed at which a modem operates will affect the download time of
web pages and files.
 Data transmission is basically the transmission of data from one
location to another for direct use or for further processing.
 Bandwidth determines the volume of data that can be
transmitted in a given time. Usually measured in bits per second.
(bps)
Components of a WAN
 The higher the bandwidth, the quicker the data will flow
along the line…
 Web pages load quicker.
 Multimedia is downloaded faster.
 Internet connection is faster.
 Less network traffic.
 Quicker response time.
Components of a WAN
 Narrowband is used to refer to data transmission over a
telephone line using an analogue modem that can transmit
data at speeds up to 56 Kbps or (56 Kbaud)
 To access the Internet, narrowband users dial up a remote
computer that provides Internet access.
 Broadband refers to data transmission using ADSL
(Asymmetric Digital Subscriber Line) and cable. ADSL is a
means of transmitting digital signals using telephone lines and
can be many times faster than narrowband.
 A network of ATMs is a WAN.
The Internet
 Internet is the largest WAN – an international network of
networks that connects computer worldwide.
 WANS can be connected together using the Internet, leased
lines or satellite links.
 It consists of:
WWW –World Wide Web.
Forums where people can seek help and advice about a topic.
Research databases used by universities and large companies.
USENET – discussion groups about a specific subject from the
latest boy band to favorite pets – for example Google Groups
 Email and Instant Messaging systems.




The Internet
 Note that no-one ‘owns’ the Internet.
 Each of it is made up of individual networks that some has
put together and then linked to the Internet.
 However, each network has to obey Internet standards in
order to connect and there are groups set by the US
Government that organize things such as web addresses.
 The Internet is not the same as the WWW.
 The Internet is to the World Wide Web as Europe is to
Germany.
Connecting to the Internet - ISP
 An ISP (Internet Service Provider) sells Internet access to
companies and individuals.
 It provides web servers which connect to the Internet.
 As ISP will provide it’s customers with a wide range of
services:
 Bandwidth options.
 Email service.
 Web hosting.
 Online and Telephone assistance.
Connecting to the Internet - ISP
 Dial up or narrow band
 Is when the computer dials a phone number to connect you to
your ISP using a telephone line.
 Broadband
 A single cable that can provide cable TV, telephone and Internet
services.
 Available over a telephone line or cable, or mobile telephone
network.
Connecting to the Internet - Hardware
 A computer
 An internal or external modem or similar device
 Satellites, fiber optic cables or radio waves.
Connecting to the Internet – Software
 TCP/IP (Transmission Control Protocol/Internet Protocol)
 A set of protocols used to transfer data from one computer to
another over the Internet.
 A protocol is a set of rules that defines how computers interact
or communicate with each other.
 Most modern operating systems implement the TCP/IP
standard.
Connecting to the Internet – Software
 Browser software allows users to view and use the web pages
on the Internet.
 An Address Bar.
 A Navigation Bar.
 A Bookmark/Favorites Option.
 A Search Engine.
 A History Button.
 Browser Setting and Internet Options e.g. Filtering.
Connecting to the Internet - others
 Internet address
 Every device on the Internet has an unique address that
identifies it. This address is a number called the IP address.
 The IP address could be static (it remains the same every time
you connect to the Internet) or dynamic (a temporary address
that changes each time you connect to the Internet
 Web addresses or URLs
WWW
 The World Wide Web is a multimedia service that runs on the
Internet.
 The web consists of hypertext and hypermedia documents.
 This documents contains hyperlinks to other documents
located on the same computer or on another computer in any
part of the world.
 All the information that can be accessed via the Internet is
often called Cyberspace.
Uniform Resource Locators
 Uniform Resource Locators is the full form of URL.
 Example: http://go.microsoft.com/fwlink/?LinkId=69157
 TypeOfResource://HostComputer.Domain/Directory/Sub
Directory/Filename.Extension
 http://www.cislagos.com/students/exams/timetable.doc
File Names and Extensions
 Microsoft Word: timetable.doc
 Microsoft Excel: timetable.xls
 Microsoft PowerPoint: timetable.pptx
 Microsoft Access: timetable.dbs
 A Text Editor: timetable.txt
 A Zipped File: timetable.zip
 A Webpage: timetable.html
 An Adobe File: timetable.pdf
 A Graphics File: timetable.gif
What can you do on the Internet and
on the Web?
 View web pages
 Use a search engine to find pages you want
 Send and receive e-mails
 Shop online (e-commerce)
 Online banking (e-commerce)
 Bet online
 Access customer support
 Software download and distribution
 Access and discuss information via mailing lists, bulletin boards and news groups
 Chat online
 Video conferencing
 Web broadcasting
 Set up your own website or blog or wiki
 Use social networking sites
Task
Research on any two of the following:
 Online shopping
 Online banking
 Web broadcasting
 Social networking
Discuss the advantages and disadvantages as well as the impact
on society.
Choose an organization or business as a case study.
Online Shopping
Online shopping is the ability to shop over the internet.
Advantages
 Convenience –You don’t have to wait in lines to pay for your
goods.You can easily find information about availability and shop
at any time of the day.You can do it at your own time and pace.
 Better prices – Cheaper deals because goods come directly from
manufacturers. Many online stores have special offers and
discounts.
 Variety – there is typically a wider range of products on online
shopping sites.You needn’t compromise your choices because of
lack of options.
Online Shopping
Disadvantages
 You do not physically see the items, and if you are shopping at an
online clothing store you are never too sure if the items are your
size.
 You may have to wait a while before the items arrive especially if
you are buying something internationally.You also have to pay
postage sites.
 Chances of mishandling. If your goods never arrive then you have
no location to go back too.
 Online security – Making payments are not always safe and
hackers may get into your bank details.
 Knowledge of Operating Computer – Older people especially
may find some websites difficult to use and are not very confident
in using a computer therefore will not use online shopping.
Online Shopping
Impact On Society
 The High Street may shrink as we start to do more of our
shopping online. Finding exactly what we want. Finding the
cheapest or most competitive pricing.
When it works internet shopping can be great. When it fails it can
really mess things up. Delays in dispatching orders; orders that
never show up; incorrect orders etc all cause problems.
Sometimes it is a dive into the unknown. At present credit card
companies are taking the brunt of this. Sooner or later they will
change their way of operating to cut their losses.
I also think we may start to buy more. It is far to easy to buy over
the internet. Far to easy to shop with instant credit.
Online Shopping - Amazon
 Amazon allows you to purchase materials cheaply without any limit and





without any restrictions.
It gives you the chance to make a free selection and comparison between
prices of goods
You have the luxury of shopping from anywhere around the world at any
time
However, there are occasional security infringements
Accordingly, many losses equally occurred to the customer and the
merchant due to such acts of hackers who reveal the information and
credit cards details.
In addition, the Electronic Marketing caused many merchants, agents
and monopolists to be vanquished because it gave the chance for direct
communications between the producer and the consumer without
passing through them; as such, many of such merchants have been
yielded away from the way of this new technology.
Web Broadcasting
Web broadcasting is being able to stream videos on the internet.
Advantages
 Easily watch videos at a click of a button
 You can easily upload videos and share between friends
 Available globally
 Ability to spread information
Disadvantages
 Cannot control content on site
 Slow internet connection can make using
the website very irritating
Web Broadcasting - Youtube
•It is public, so anyone can see the videos you post
•Anyone for the most part can post a video
•There is violence on some of the videos on the site
•There are explicit videos
•There is some animal abuse in the videos
•Teens are recording violence to post on YouTube
•There could be issues of privacy invasion
•There could be copyright infringement issues
Web Broadcasting - Youtube
•Using YouTube to reach the media is cheap and easy.
•YouTube will show most any video
•The service is clean and clear
•YouTube has a wide variety of videos, infomercials, how to videos and much more
•You can stay up to date with the new videos at YouTube
•Expressing your creativity through YouTube is a major benefit
•Getting to know people through YouTube is great
•Learning through YouTube is great
•You can get a good deal of information to many people in a short amount of time
•Becoming a member is easier
•Ease of use
•No need for tons of equipment, computer, video equipment, microphone and
editing software
•Saves money on marketing