chapter 1 stud

8/8/2019 Chapter 1 Stud

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INTRODUCTION TOTHE INTERNET

CHAPTER 1


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Learning Objectives

yDescribe the supporting structure forInternet.

y

To list different types of Internetcomponents.

yDifferentiate between Internet and Worldwide Web.

y Identify protocols supporting the Internetand World Wide Web.


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Whatisthe Internet?

y Definition:Worldwide collection of computer networks,cooperating with each other to exchange data using acommon software standard.

o Network:Computers wired or connected together in a way that letsthem share data, resources, devices, etc.

y WorldWide Web (WWW): is a protocol that can beused for communication on the Internet.

y Hypertext Transfer Protocol (HTTP): The term thatdescribes the way in which Web transfers information.


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Whatisthe Internet? (Cont..)

y Client: Are users of the Internet.

y Web Server: is a 24 hours, 7 days a week

communication application that waits for requests byclients using Web browsers.


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Different between InternetandWWW

y The Internet refers to the physical connectionbetween computer networks all over the world.

y The WWWor Web is simply a special method ofsending information over the Internet (using URLs,HTTP, etc).

y No physical difference between the Internet andWeb, but differ in terms of communication protocol.


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Developmentofthe Internetin Malaysia

Year Event

1988 Establishment of Rangkaian KomputerMalaysia (RANGKOM) network which

connects the universities and research centres.

1991 JARING network was introduced and becamethe first Internet Service Provider (ISP).

1997 Telekom Malaysia Berhad through itssubsidiary, TM-Net became the second ISP.


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Howdoesthe Internetwork?

y Amessage sent from one computer to another is firstbroken up into small packets.

y The sending computer then passes those packets

along to the next connected Internet machine.y This process will repeat until the packets reach the

destination machine.

y IP can't ensure that the packets arrived in the correct order.

y That's the job of another protocol: TCP (TransmissionControl Protocol).


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Whatis TCP?

y Ensures that all the packets sent from one machineto another are received and assembled in the correctorder.

y Should any of the packets get "dropped" duringtransmission, the destination machine uses TCP torequest that the sending machine resend the lostpackets, and to acknowledge them when they arrive.

y The Transmission Control Protocol(TCP) part formsthe data into bite-size chunks


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Whatis TCP? (Cont)

y The Internet Protocol (IP) part routes them to itsdestination.

y The reasons why files are divided into packets are:

The packets may be routed to best utilize network resources To ensure the file arrives correctly.


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What is an IP address?

y Every machine on the Internet has a uniqueidentifying number, called an Internet Protocol, IPaddress.

y Example : 216.27.61.137y Computers understands IP address as binary

numbers, which are separated by dots.

y Some IP addresses are restricted from use.

y 0.0.0.0 - for default networks

y 127.0.0.1 - local hosts

y 255.255.255.255 - broadcasting


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Whatis DNS?

y "DNS" stands for the "Domain Name System".Sometimes, this acronym is used to mean the"Domain Name Service".

y Examples : "www.microsoft.com" orwww.yahoo.com

y It is used to uniquely identify a computer/system.


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Whatis DNS?(Cont)

y ADNS name is made of a domain and one or moresubdomains.

Example: [email protected] mohd username

mmu host computer

edu next-level domain or subdomain

my highest-level domain


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Whatis DNS?(Cont)

y Organizational Domain

Domain Meaning

.com commercial

.edu educational

.gov government

.mil military

.org non-profit organization

.net network organization


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Whatis DNS?(Cont)

y Geographical Domain

Domain Meaning

.my Malaysia

.uk United Kingdom

.jp Japan

.au Australia

.nz New Zealand

.fr France


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Internet Architecture

y Two Tiered ArchitectureYour computer runs software

called the client and itinteracts with another software

known as the server located ata remote computer.

The client is usually a browsersuch as Internet Explorer orNetscapeNavigator.

Browsers interact with theserver using a set ofinstructions called protocols.


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Internet Architecture (Cont)

y Three Tiered Architecture

y Client Tier

User Interface

Data Input Validation Rules Example : HTML pages

y Middle Tier

Business Rules and Logic

Example :

ASP. Scripts

y Data Tier

Database Access

Database Integrity

Example : Access, MySQL,etc.


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Requirementto Access Internet

y What do you need?

Computer

Modem

An account registered with the Internet Service Provider (ISP) Communication software

Internet software called client (web browsers)


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Howto Connecttothe Internet?

y Through Internet Service Providers (ISP)-local or national companies that provide unlimitedpublic access to the Internet and World Wide Web

for a flat rate.y In Malaysia, there are two ISPs:

JARING (Joint Advanced Research IntegratedNetworking)

TMNet


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Waysto be Connectedtothe Internet

a) Dial Up

y It replaces the high-speed network cable with alower-speed connection using a modem and the

public phone system.y The user runs a special dialler program to provide for

the TCP/IP protocol, which controls the modem andmakes the Internet connection.

y The Internet Service Provider (ISP) at the other endof the telephone line call maintains a port thatresembles the one you might have on campus.


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Waysto be Connectedtothe Internet(Cont)

b)LeasedLines

y Apermanent telephone connection between twopoints set up by a telecommunications common

carriery used by businesses to connect geographically distant

offices

y The fee for the connection is a fixed monthly rate.


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Waysto be Connectedtothe Internet(Cont)

c)Broadband

y High-speed Internet connection (sometimes referredto as ADSL.

y It's capable of sending data over 10 times (up to 40times faster for business connections) the speed of astandard modem.

y Its always 'on.


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TypesofWeb Pages

a) PortalWeb Page

y Aportal web page offers a variety of Internet Servicesfrom a single, convenient location. Most popular

offer the following free services: search engine; local,national and worldwide news; sports and weather;free personal Web pages; references tools, etc.

y Some portal also has Web communities

y Wireless Portal


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TypesofWeb Pages (Cont)

b) NewsWeb Page

y Anews Web page contains newsworthy materialincluding stories and articles relating to current

events, life, money, sports and the weather.Newspapers and television and radio stations aresome of the media that maintain news Web pages.


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c) InformationalWeb Page

y It contains factual information. It providesinformation such as tax codes, public transportation

schedules and published research findings.

d)Business/MarketingWeb Page

y It contains content that promotes or sells products orservices.


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e) AdvocacyWeb Page

y It contains content that describes a cause, opinion,or idea.

f) PersonalWeb Page

y Aprivate individual who normally is not associatedwith any organization often maintains a personalWeb page.


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Componentsofthe Internet

a) Chat

y Yahoo Messenger, IRC (Internet Relay Chat) is used for livediscussions on the Internet.

b)Email

y Exchanging electronic letters, messages, and small files.


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Componentsofthe Internet (Cont)

c) FTP

y File Transfer Protocol is the most common method oftransferring files between computers via the Internet.

y

Allows you to examine, send and receive files from othercomputers over the Internet.

y FTP server is a computer that allows users to upload anddownload files using FTP.

y

FTP site is a collection of files including text, graphics,audio, video and program files that reside on a FTP server.


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c) FTP (Cont)

y The hostcomputer is a remote computer that isaccessible via the Internet.

y

The clientcomputer is usually considered your owncomputer.

y The transfer of files from the host computer to the clientcomputer is known download and from the clientcomputer to the host computer as upload.


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c) FTP (Cont)


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d) Hosting

y Making information available to others on theInternet.

e) MailingListsy E-mail messages forwarded to everyone on a special

interest list.

f) Search Engines

y These tools are really a part of the World Wide Weband are often used when looking for information

because the Web has grown so large and is withoutany inherent organizational structure


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g) Telnet

y Creation of a dumb terminal session to a hostcomputer in order to run software applications on

the host system.h) Usenet

y Newsgroups for receiving news and sending outannouncements.

i)WorldWideWeb

y This is largest, fastest growing, part of the Internet,the part for which Internet browsers like NetscapesNavigator and Microsofts Explorer were designed.


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j)Browser

y AWeb Browser is a program that allows you to viewand explore information on the Web. E.g: IE,

Netscape Navigator.k) HTTP (HyperText Transfer Protocol)

y HTTP, short for Hypertext Transfer Protocol, is theprotocol for transferring hypertext documents that

makes the World Wide Web possible.

y Astandard Web address (such ashttp://www.yahoo.com/) is called a URL; the prefix(http in the example) indicates its protocol.


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l) HTML (Hypertext Markup Language)

y Language used to write web page documents.

m) URL (Uniform ResourceLocator)

y URL stands for Uniform Resource Locator, and isused to specify addresses on the World Wide Web.

y AURL is the fundamental network identification forany resource connected to the Web (e.g., hypertextpages, images, and sound files).

y URLs have the following format:protocol://hostname/other_information


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n)Webpage

y Web Pages make up what you see on a screenanytime you type in a web address, click on a button,

or type in a query on a search engine.0) Hypertext

y Hypertext is text which is not constrained to belinear.

y Hypertext is text which contains links to other texts.

y HyperMedia is a term used for hypertext which is notconstrained to be text: it can include graphics, videoand sound


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p) Hyperlinks

y Ahyperlink, or hot link, is a selectable element in anelectronic document that serves as an access point to

other electronic resources.y Click the hyperlink to access the linked resource.

y Common types of hyperlinks include buttons, icons,image maps, and clickable text links.

q) Homepage

y When you browse the World Wide Web you'll see theterm home page often. Think of a home page as thestarting point of a website.


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r)Website

y Awebsite has one or more related web pages,depending on how it's designed.

y Web pages on a site are linked together through asystem of hyperlinks, enabling you to jump betweenthem by clicking on a link.

s) Netiquette

y "Netiquette" is network etiquette, the do's and don'tsof online communication. E.g: Avoid using all caps,use emoticons, careful not to discriminate others.


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Advantageofthe Internet

y 24 hours service, anywhere around the world.(unless the network is down).

y Exchange electronic mail (E-mail) with friends and

colleagues with accounts on the Internet.y Post information for others to access, and update it

frequently.

y Access multimedia information that includes sound,

photographic images and even video.


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THANKYOU

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