overview of the internet and the world wide web

7/29/2019 Overview of the Internet and the World Wide Web

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Overview of theInternet and the

World Wide WebCS 32.1

Web Programming

JCObispo


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Terminologies

Network any collection of computers that can

communicate with each other

Protocol a system of digital message formats

and rules for exchanging those messages in or

between computing systems and in

telecommunications

CS 32.1 Web Programming

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The Internet

The worldwide network of all computers (or

networks of networks) that communicate using

a particular protocol for routing data from onecomputer to another


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ARPA

Advanced Research Project Agency of the US

Department of Defense

Sponsored a conference which many ARPA-

funded graduate students were brought

together

ARPA rolled out blueprints for networking the

main computer systems of ARPA-fundeduniversities and research institutions


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ARPA

Computers were connected with

communication lines with speed of 56 Kbps

Connection was then over telephone lines at

110 bits per second

Talked about communicating with UNIVAC 1108

at the University of Utah for calculations

relating to their research on computer graphics

Implemented it and called it ARPAnet


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ARPAnet

Enabled researches to communicate easily via

electronic mail (e-mail)

Network was designed without centralized

control

If one portion fails, there are still other available

paths


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TCP

Transmission Control Protocol

Set of rules for communicating over ARPAnet

Ensures that messages were properly routed

from sender to receiver


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IP

Internet Protocol

True Network of networks

Variety of software and hardware appeared

Assure that these variety of products will

communicate with each other


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TCP/IP

Combination of TCP and IP

Current architecture of the internet

Enables computers to talk to each other


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TCP/IP

Inclusions:

HTTP Hypertext Transfer Protocol

Defines how websites are formatted andtransmitted through the network

FTP File Transfer Protocol

Protocol for exchanging (uploading anddownloading) files over a network

Telnet Terminal Emulator Allows a user to control a web server from a remote

location


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Internet Use

Originally limited to universities and research

institutions

Military adopted the technology

Later, the government allowed for commercial

purposes


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Internet Use

Resentment of the research and military

communities Net will be saturated with many

users Opposite occurred

Different businesses enhanced and developed the

Internet presence

Generated fierce competition amongcommunication carriers and hardware and software

suppliers to meet increased infrastructure demand


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Bandwidth

Bandwidth increased while hardware costs

plummeted

Bandwidth information-carrying capacity of

communication lines

Internet helped in the economic growth of

many industrialized countries, especially US


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WWW

World Wide Web

Allows computers to locate and view multimedia-

based documents Texts, graphics, animations, audios or videos

Introduced by Tim Berners-Lee of CERN in 1989

Invented the Hypertext Markup Language (HTML)

based on the Standard Generalized MarkupLanguage a standard for business data interchange


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WWW

A complex, international, cross platform, cross

language, cross cultural mesh of servers, clients,

users, databases, and quite a few artificialintelligences all talking, working, searching,

viewing, accessing, downloading


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W3C

World Wide Web Consortium (www.w3.org)

Founded by Tim Berners-Lee in 1994

Devoted in developing nonproprietary,

interoperable technologies for the web

Main goal is to make the web universally

accessible


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W3C

Has representatives from Apple, Microsoft,

Adobe, Sun, Google, Oracle, IBM, and many

more.

Produced may popular technologies used by

many popular software companies including

HTML, XML, Web Service Protocol, PNG, etc.


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Viewing a Webpage

Suppose you want to view www.xu.edu.ph

A server contains all the files of the XU website

The browser will look for a file named

index.html


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http://www.xu.edu.ph/http://www.xu.edu.ph/


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Viewing a Webpage


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CLIENT SERVER

(1) Browser connects

to a server and requests

a page

(4) Computer

running a web

browser accessing

a website displays

the webpage

(2) Server

processes the

request

(3) Server sends back

the requested page


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Viewing a Webpage

HTML content

CSS style

JavaScript behavior


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Client-side Programming VS

Server-side Programming

Client-side programming is executed by the

client computer

JavaScript and VBScript

Server-side Programming is executed by the

server computer

Server processes the request, transforms the

output into HTML code and sends it back to theclient

PHP, ASP, ColdFusion


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Communicating over the Internet

Computers and servers have IP addresses

32-bit number usually expressed as an octet

Example: the IP ofwww.xu.edu.ph is

203.177.182.16.

To access the XU website, you look for

http:// 203.177.182.16


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http://www.xu.edu.ph/http://www.xu.edu.ph/


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Communicating over the Internet

However, it is difficult to remember IP

addresses

In solution, websites have domain names which

are readable counterparts of IP addresses

Domain Name Servers (DNS) translate domain

names into IP addresses


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Domain Names

For example:

www.xu.edu.ph

www host name

xu domain name

edu top-level domain name

ph country


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Evolution of the Web Technology

Web 1.0

First generation web

WYSIWYG

Composed of static pages

One-way broadcasting only owner of the site

can publish information


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Web 2.0

Second generation web

Interactive and dynamic Web

People can collaborate and share information

online

Refers to the transition from static HTML to

dynamic HTML

Also regarded as social web


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Web 2.0 Applications and Solutions

W3C updated HTML to XHTML 2.0

Contributing vendors did not warmly accept the

standard Subsequent standard was introduced called

HTML5 by the Web Hypertext ApplicationTechnology Working Group

XHTML died in the vine and major technologycompanies pledge to support HTML5, some areusing it already


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Web 2.0 Applications and Solutions

All web browsers adopted the HTML4 standard

Microsoft was the weakest company in

supporting Web HTML standards Until the release of Internet Explorer 8

New web browsers (Safari, Opera, Chrome,Firefox) and new web-enabled devices (iPhone,Android, Pre, Blackberry) agrees that HTML5 isthe next standard, and they are alreadysupporting it


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Web 3.0

Future Web Technology intelligent web

Semantic Web, personalization, intelligent

search and behavioral advertising

Initiative was inspired by Berners-Lee of a more

flexible, integrated, automatic and self-adapting

web, providing a richer and more interactive

experience for users


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The Semantic Web

The Semantic Web will bring structure to the

meaningful content of Web pages, creating an

environment where software agents roamingfrom page to page can readily carry out

sophisticated tasks for users. Tim Berners-Lee


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Semantic Web Stack

This figure

illustrates the

architecture ofthe Semantic

Web


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The Semantic Web Components

URI identifiers

UNICODE character set

XML syntax

RDF data interchange

RDFS taxonomies

SPARQL query language

OWL ontologies

RIF rules


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Web 3.0 State of Standardization

Standardized:

UNICODE

URI

XML

RDF and RDFS

SPARQL

OWL


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Ongoing:

RIF

Not yet Realized:

Unifying Logic

Proof


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Review Questions

What is the difference between the INTERNET

and the WORLD WIDE WEB?

Compare the three versions of the webtechnology (Web 1.0, 2.0 and 3.0)

How does your web browser access a website?

How would you respond if someone asks you

where in the world is the central computer

where the internet is stored?


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Reflection

Do you agree that the internet and the World

Wide Web are listed as one of the most

important and profound creations ofhumankind?


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overview of the internet and the world wide web

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