Computer Network and Internet

1. 1
CSCA0201
FUNDAMENTALS OF COMPUTING
Chapter 9
Computer Network
CSCA0201
FUNDAMENTALS OF COMPUTING
Chapter 8
Malware
CSCA0201
FUNDAMENTALS OF COMPUTING
Chapter 7
Software
CSCA0201
FUNDAMENTALS OF COMPUTING
Chapter 6
Operating Systems
CSCA0201
FUNDAMENTALS OF COMPUTING
Chapter 5
Storage Devices
CSCA0201
FUNDAMENTALS OF COMPUTING
Chapter 10
Computer Network and
Internet

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Chapter 10 Computer Network and Internet
• A computer network is a system in which multiple
computers are connected to each other to share
information and resources.
• Computers on a network are sometimes called
nodes.
• Computers and devices that allocate resources for a
network are called servers.

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Chapter 10 Computer Network and Internet
Characteristics of a Computer Network
• Share resources from one computer to another.
• Create files and store them in one computer, access
those files from the other computer(s) connected over
the network.
• Connect a printer, scanner, or a fax machine to one
computer within the network and let other computers
of the network use the machines available over the
network.

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Chapter 10 Computer Network and Internet
Computer Network Requirements
• Network Cables
• Distributors
• Routers
• Internal Network Cards
• External Network Cards

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Chapter 10 Computer Network and Internet
Computer Network Requirements
Network Cables
• Network cables are used to connect computers. The
most commonly used cable is Category 5 cable RJ-
45.

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Chapter 10 Computer Network and Internet
Computer Network Requirements
Distributors
• A computer can be connected to another one via a serial port
but if we need to connect many computers to produce a
network, this serial connection will not work.
• The solution is to use a central body to which other computers,
printers, scanners, etc. can be connected and then this body will
manage or distribute network traffic.

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Chapter 10 Computer Network and Internet
Computer Network Requirements
Router
• A router is a type of device which acts as
the central point among computers and
other devices that are a part of the
network.
• It is equipped with holes called ports.
• Computers and other devices are
connected to a router using network
cables.
• Now-a-days router comes in wireless
modes using which computers can be
connected without any physical cable.

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Chapter 10 Computer Network and Internet
Computer Network Requirements
Network Card
• Network card is a necessary
component of a computer without
which a computer cannot be
connected over a network.
• It is also known as the network
adapter or Network Interface Card
(NIC).
• Most branded computers have
network card pre-installed.
• Network cards are of two types:
Internal and External Network Cards.

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Chapter 10 Computer Network and Internet
Types of Computer Network
Local Area Network (LAN)
• A LAN connects network devices over a relatively short
distance.
• A networked office building, school, or home usually
contains a single LAN.
• A LAN may be wired, wireless, or a combination of the two.

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Chapter 10 Computer Network and Internet
Types of Computer Network
Metropolitan Area Network (MAN)
• A metropolitan area network (MAN) is a large
computer network that usually spans a city or a large
campus.
• A MAN is similar to a LAN but spans an entire city or
campus. MANs are formed by connecting multiple
LANs.
• A MAN typically covers an area of between 5km and
50km diameter.

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Chapter 10 Computer Network and Internet
Types of Computer Network
Wide Area Network (WAN)
• A wide area network (WAN) is a network that exists
over a large-scale geographical area.
• A WAN connects different smaller networks, including
LANs and MANs.
• This ensures that computers and users in one
location can communicate with computers and users
in other locations.

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Chapter 10 Computer Network and Internet
The Internet
• A global network connecting
millions of computers
• More than 100 countries are
linked into exchanges of data,
news and opinions.
• The Internet links are
computer networks all over
the world so that users can
share resources and
communicate with each
other.

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Chapter 10 Computer Network and Internet
Internet Connection
• To gain access to the internet, the user has to
register to any Internet Service Provider (ISP).
• Types of Internet connection:
– Dial-up
– Digital Subscriber Line
– Satellite
– 3G and 4G

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Chapter 10 Computer Network and Internet
Internet Connection
Dial-up
• Refers to connecting a device to a network via a
modem and a public telephone network.
• Because dial-up access uses normal telephone
lines, the quality of the connection is not always
good and data rates are limited.
• Speed: 2400 bps to 56 Kbps

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Chapter 10 Computer Network and Internet
Internet Connection
Digital Subscriber Line (DSL)
• Broadband connection – faster than dial-up
connection
• Connects through phone lines, but does not require
phone service
• Always on
• Internet and phone can be used in the same time
• Speed: 128 Kbps to 8 Mbps

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Chapter 10 Computer Network and Internet
Internet Connection
Satellite
• Broadband – faster than dial-up, but data is delayed
• Connects via satellites
• Can be affected by rain and snow
• Does not require phone lines and cables
• Can be use anywhere around the world
• Speed: 6 Mbps or more

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Chapter 10 Computer Network and Internet
Internet Connection
3G and 4G
• Available for mobile phones, computers and tablets
• Connects wirelessly through 3G/4G provider
• Can access Internet anywhere
• Slower than DSL and Cable connection
• Speed:
– 4G: 100 Mbps to 1 Gbps
– 3G: 7.2 Mbps or 52 Mbps

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Chapter 10 Computer Network and Internet
Internet Connection
Wireless
• Wireless is the term used to describe any computer
network where there is no physical wired connection
between sender and receiver, but rather the network
is connected by radio waves and/or microwaves to
maintain communications.
• Wi-Fi hotspots and wireless LANs are also options
for wireless Internet connectivity.
• Speed: 30 Mbps or more

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Chapter 10 Computer Network and Internet
Choosing Internet Service Provider (ISP)
Below are some things to consider as you research
ISPs:
• Coverage
• Speed
• Price
• Ease of Installation
• Service Record
• Technical Support
• Contract Terms

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Chapter 10 Computer Network and Internet
How Internet Works?
• Because the Internet is a global network of
computers each computer connected to the Internet
must have a unique address.
• This address is known as an IP address.

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Chapter 10 Computer Network and Internet
Internet Requirement
• Computer with modem/router/network card.
• Internet account with ISP.
• Application software:
– Web browser (Firefox, Chrome)
– Email client (MS Outlook)
– Plugins software (Adobe Reader, Flash Player)
• Optional: Speaker, Printer, Webcam

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Chapter 10 Computer Network and Internet
Internet Usages
• Communication
• Send and receive emails
• Download files
• Post your opinion to a newsgroup
• Chatting
• Surf the world wide web
• Business
• Shopping
• Entertainment

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Chapter 10 Computer Network and Internet
Internet Applications
• An Internet application is an interactive, compiled
application that can be accessed through a
corporate or through the Internet.
• Internet applications can perform complex business
processes on either the client or the server.
• The application uses the Internet protocol to receive
requests from a client, typically a Web browser,
process associated code, and return data to the
browser.

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Chapter 10 Computer Network and Internet
Internet Applications
• The World-Wide Web (WWW)
• Electronic Mail (E-Mail)
• File Transfer Protocol (FTP)
• Search Engine
• Chatting
• Video Conferencing
• E-Commerce

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Chapter 10 Computer Network and Internet
World Wide Web (WWW)
• The World Wide Web is a
system of interlinked
hypertext documents
accessed via the Internet
• With a web browser, one
can view web pages that
may contain text, images,
videos, and other
multimedia and navigate
between them via
hyperlinks

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Chapter 10 Computer Network and Internet
World Wide Web (WWW)
• It use a protocol called HTTP – Hypertext Transfer
Protocol
• HTTP defines how messages are formatted and
transmitted, and what actions Web servers and
browsers should take in response to various
commands.

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Chapter 10 Computer Network and Internet
World Wide Web (WWW)
• A Uniform Resource Locator, or URL is the
address of a document you'll find on the WWW.
• The elements in a URL:
Protocol://server's address/filename
• Example:
http://www.google.com/index.html

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Chapter 10 Computer Network and Internet
World Wide Web (WWW)
Types of website:
• Static
– A static website is one that has web pages stored
on the server in the format that is sent to a client
web browser. It is primarily coded in Hypertext
Markup Language (HTML)
• Dynamic
– A dynamic website is one that changes or
customizes itself frequently and automatically,
based on certain criteria.

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Chapter 10 Computer Network and Internet
Electronic Mail (Email)
• The transmission of messages over communications
networks.
• It is a fast and efficient way to communicate with
friends or colleagues.
• You can communicate with one person at a time or
thousands; you can receive and send files and other
information.

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Chapter 10 Computer Network and Internet
Electronic Mail (Email)
• Basic email functions:
– send and receive mail messages
– save your messages in a file
– print mail messages
– reply to mail messages
– attach a file to a mail message

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Chapter 10 Computer Network and Internet
Electronic Mail (Email)
• Email address
someone@mail server
• The email address has three parts:
– a user name
– an "at" sign (@)
– the address of the user's mail server
• Example
Harris@ftms.edu.my

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Chapter 10 Computer Network and Internet
Email Client
• An email client is a computer program used to
manage a user's email.
• Popular email clients include Microsoft Outlook,
Pegasus Mail, Mozilla's Thunderbird, and Apple
Inc.'s Mail.

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Chapter 10 Computer Network and Internet
Web-based mail
• Is an e-mail service
intended to be primarily
accessed via a web
browser.
• Very popular webmail
providers:
– Gmail
– Yahoo! Mail
– Hotmail
• Web mail is popular as it
allows you to send or
receive e-mail from
anywhere.

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Chapter 10 Computer Network and Internet
File Transfer Protocol (FTP)
• The protocol for exchanging files over the Internet.
• Used for moving files between two hosts on a
TCP/IP network.
• FTP is most commonly used to download a file from
a server using the Internet or to upload a file to a
server.

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Chapter 10 Computer Network and Internet
Search Engine
• A search engine is designed
to search for information on
the internet.
• Search engine presents the
search results in the form of a
search results list.
• The search results can be
web pages, images, videos,
and other type of files.
• Example:
– Google
– Bing

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Chapter 10 Computer Network and Internet
Chatting
• Chatting is the other
method for Internet
conversation.
• It enables people
connected anywhere on
the Internet to join in live
discussions.
• Chat sessions allow
many users to join in the
same free-form
conversation, usually
centered around a
discussion topic.

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Chapter 10 Computer Network and Internet
Video Conferencing
• A videoconference or video conference is a set of
interactive telecommunication technologies which
allow two or more locations to interact via two-way
video and audio transmissions simultaneously.

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Chapter 10 Computer Network and Internet
Video Conferencing
The other components required for a videoconferencing
system include:
• Video input and output
• Audio input and output
• Data transfer
• Computer

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Chapter 10 Computer Network and Internet
E-Commerce
• Electronic commerce or E-
Commerce consists of the
buying and selling of
products or services over
electronic systems such as
the Internet and other
computer networks.
• It includes the entire online
process of developing,
marketing, selling,
delivering, servicing and
paying for products and
services.

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Chapter 10 Computer Network and Internet
E-Commerce
Some common applications related to electronic
commerce are the following:
• Domestic and international payment systems
• Group buying
• Automated online assistants
• Online shopping and order tracking
• Online banking
• Shopping cart software
• Electronic tickets