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Computer Confluence 7/e. © 2006 Prentice-Hall, Inc. Computer Confluence 7/e. Chapter 9 Inside the Internet and the World Wide Web . © 2006 Prentice-Hall, Inc. Computer Confluence 7/e Chapter 9 Objectives. Explain how and why the Internet was created

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Computer confluence 7 e

Computer Confluence 7/e

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e1

Computer Confluence 7/e

Chapter 9

Inside the Internet and the World Wide Web

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 objectives

Computer Confluence 7/e Chapter 9Objectives

Explain how and why the Internet was created

Describe the technology that is at the heart of the Internet

Describe the technology that makes the Web work as a multimedia mass medium

Discuss the tools people use to build Web sites

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 objectives cont

Computer Confluence 7/e Chapter 9Objectives (cont.)

Discuss the trends that are changing the Internet and the way people use it

Discuss some of the most important social and political issues raised by the growth of the Internet

Describe various ways that governments restrict access to the Internet

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 arpanet pioneers build an unreliable network on purpose

Computer Confluence 7/e Chapter 9 ARPANET Pioneers Build an Unreliable Network ... on Purpose

The Advanced Research Projects Agency NETwork (ARPANET) is the predecessor to the Internet:

Developed at the request of the Department of Defense by a team of visionary computer scientists

Launched in 1969

Its peer-to-peer networking philosophy and protocols were copied in other networks in the 1980s

Disbanded in 1990, having fulfilled its research mission, but its technology spawned the Internet

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside the internet

Computer Confluence 7/e Chapter 9 Inside the Internet

Counting Connections

The Internet: an interconnected network of thousands of networks

Links academic, research, government, and commercial institutions

Connects computers to about every country in the world.

Growing too fast to measure its growth

Too decentralized to quantify

A network with no hard boundaries

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside the internet1

Computer Confluence 7/e Chapter 9 Inside the Internet

Internet Protocols

Transmission Control Protocol/Internet Protocol, TCP/IP…

At the heart of the Internet

Allows cross-network communication

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside the internet2

Computer Confluence 7/e Chapter 9 Inside the Internet

TCP breaks messages into packets

Each packet has all the information needed to travel from network to network

Host systems called routers determine how to route transmissions

IP is the address for the packets

Each Internet host computer has a unique IP address

Each address is comprised of four sets of numbers separated by periods, such as 123.23.168.22

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside the internet3

Computer Confluence 7/e Chapter 9 Inside the Internet

Internet Addresses

The host is named using DNS (domain name system), which translates IP addresses into a string of names

Top-level domains include:

.edu - educational sites

.com - commercial sites

.gov - government sites

.mil - military sites

.net - network administration sites

.org - nonprofit organizations

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside the internet4

Computer Confluence 7/e Chapter 9 Inside the Internet

The Internet Ad Hoc Committee recently created seven additional top-level domain names:

.aero Air transport organizations

.biz Businesses

.coop Cooperative businesses such as credit unions

.info Information services

.museum Museums

.name Personal registration by name

.pro Licensed professionals, including lawyers, doctors, and accountants

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside the internet5

Computer Confluence 7/e Chapter 9 Inside the Internet

An email address includes: [email protected]

username is the person’s “mailbox”

hostname is the name of the host computer and is followed by one or more domains separated by periods:

host.domain

host.subdomain.domain

host.subdomain.subdomain.domain

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside the internet6

Computer Confluence 7/e Chapter 9 Inside the Internet

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside the internet7

Computer Confluence 7/e Chapter 9 Inside the Internet

Internet Access Options

Direct (Dedicated) Connection

Computer has its own IP address and is attached to a LAN

No need to dial up

Files are stored on your computer

Quick response time

Dialup Connection

Limited connection using a modem

Full access dialup uses SLIP or PPP via modem

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside the internet8

Computer Confluence 7/e Chapter 9 Inside the Internet

Broadband Connections

DSL Service

Newer, faster, and cheaper than ISDN

Can share phone line with voice traffic

Cable Modem Connection

Allows Internet connections using shared TV cables

Can exceed DSL speeds

Carries increased privacy and security risks

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside the internet9

Computer Confluence 7/e Chapter 9 Inside the Internet

Satellite Connection

Provides connection using DirecTV

satellite dishes

Wireless Broadband Connection

Allows multiple computers to connect to a

base station using short-range radio waves.

Internet Service Providers (ISPs)

Local ISPs provide connections through local telephone lines

National ISPs offer connections on a nationwide scale

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside the internet10

Computer Confluence 7/e Chapter 9 Inside the Internet

Internet Servers

E-mail server acts like a local post office for a particular Internet host—a business, an organization, or an ISP

File servers are common within LANs

Also used to share programs, media files, and other data across the Internet

File transfer protocol (FTP) allows users to transfer files

Download files from remote servers to their computers

Upload files to remote computers

File compression saves storage space on disk and saves transmission time when files are transferred through networks

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside the internet11

Computer Confluence 7/e Chapter 9 Inside the Internet

Application server stores applications—PC office applications, databases, or other applications

Makes them available to client programs that request them

Might be housed at an application service provider (ASP), a company that manages and delivers application services on a contract basis

Web server stores Web pages and sends pages to client Web browsers

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside the web

Computer Confluence 7/e Chapter 9 Inside the Web

Web Protocols: HTTP and HTML

WWW is a distributed browsing and searching system developed at CERN and designed to give Internet documents unique addresses

HTML was created for encoding and displaying documents

An HTML document includes code that determines the format, layout, and structure of a Web document

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside the web1

Computer Confluence 7/e Chapter 9 Inside the Web

HTML Is Not WYSIWYG (What You See Is What You Get)

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside the web2

Computer Confluence 7/e Chapter 9 Inside the Web

Browser software was built for viewing documents from remote locations

The Web is built around a naming scheme that allows every information resource on the Internet to be referred to using a uniform resource locator, or as it’s more commonly known, a URL. A typlical URL looks like this:

http://weatherunderground.com/satellite/vis/1k/US.html/

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside the web3

Computer Confluence 7/e Chapter 9 Inside the Web

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside the web4

By expanding the number of people who have the power to transmit knowledge, the Web might trigger a power shift that changes everything.

—Howard Rheingold,

Virtual Communities

Computer Confluence 7/e Chapter 9 Inside the Web

Publishing on the Web

Programs that convert document format features into HTML codes:

Microsoft Word, PowerPoint, FileMaker

Web authoring programs:

Macromedia Dreamweaver, Adobe GoLive, Microsoft FrontPage

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside the web5

Computer Confluence 7/e Chapter 9 Inside the Web

  • Tables

  • Frames

  • Forms

  • Downloadable audio and video

  • Streaming audio and video

  • Real-time live audio or video

  • 3-D environments

From Hypertext to Multimedia

Typical Web pages can contain:

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside the web6

Computer Confluence 7/e Chapter 9 Inside the Web

  • Windows Media Player

  • QuickTime

  • Shockwave/Flash

  • RealPlayer

  • Adobe Reader and Acrobat (Adobe)

Plug-ins are software extensions that add new features:

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside the web7

Computer Confluence 7/e Chapter 9 Inside the Web

Dynamic HTML

Adds more programming power to HTML by allowing code to automatically modify itself under certain circumstances

JavaScript

Scripting language for enhancing HTML Web pages

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside the web8

Computer Confluence 7/e Chapter 9 Inside the Web

  • Offer contact information

  • Think like a publisher and a multimedia designer

  • Test before you publish

  • Think before you publish

  • Keep it current

Rules of Thumb: Weaving Winning Web Sites

Start with a plan

Write for the Web

Keep it simple

Keep it consistent

Make it obvious

Keep it small

Keep it honest

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside the web9

Computer Confluence 7/e Chapter 9 Inside the Web

Dynamic Web Sites: Beyond HTML

Java

Full-featured, cross-platform, object-oriented programming language

Java Applets

Small Java programs

Automatically downloaded onto your client computer

Can run on any platform

ActiveX

Collection of programming technologies and tools for creating controls or components—

Similar in many ways to Java applets

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside the web10

Computer Confluence 7/e Chapter 9 Inside the Web

WML (Wireless Markup Language)

Helps create Web documents containing stock quotes, phone numbers, and other small nuggets of information

XML (Extensible Markup Language)

Will replace HTML plus provide additional features and extensions

XHTML

A sort of cross between HTML and XML

VRML (Virtual Reality Modeling Language)

Creates 3-D virtual worlds

SMIL (Synchronized Multimedia Integration Language)

Makes it possible to link time-based streaming media

Sounds, video, and animation can be tightly integrated

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside web applications

Computer Confluence 7/e Chapter 9 Inside Web Applications

Search Engines

Designed to make it easier to find

information on the Web

Web Crawlers or Spiders

Software robots that systematically search

the Web

Some search engines use keywords

and Boolean logic to conduct searches

Other search engines conduct searches using a hierarchical directory or subject tree

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside web applications1

Computer Confluence 7/e Chapter 9 Inside Web Applications

Meta-Search Engines (such as MetaCrawler, OneSeek, and Apple’s Sherlock)

Conduct parallel searches using several different search engines and directories

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside web applications2

Computer Confluence 7/e Chapter 9 Inside Web Applications

Portals

Web entry stations that offer quick and easy access to a variety of services

Consumer portals include search engines,e-mail services, chat rooms, references, news and sports headlines, shopping malls, and other services

Corporate portals on intranets serve the employees of particular corporations

Vertical portals are targeted at members of a particular industry or economic sector

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside web applications3

Computer Confluence 7/e Chapter 9 Inside Web Applications

  • Handle URLs with care

  • Get to know your search engines

  • If you’re in a hurry, dispense with frills

  • Organize your favorite bookmarks

  • Be selective

  • Protect your privacy

  • Be conscious of cookies

  • Shop with bots

  • Shop smart

  • Remember why you’re there

  • Think before you publish

Rules of Thumb: Working the Web

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside web applications4

Computer Confluence 7/e Chapter 9 Inside Web Applications

Push Technology: Notifications and Alerts

The Web was built with pull technology

Browsers on client computers “pull”

information from server machines

Browser asks for information

With push technology, information is

delivered automatically to the client

computer

New product descriptions

Automatic software upgrades

Updated news

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside web applications5

Computer Confluence 7/e Chapter 9 Inside Web Applications

Peer-to-Peer and Grid Computing

Peer-to-Peer (P2P) Computing

Users share music, movies,

and other files without going

through a central directory

Grid Computing

Anyone can plug in from

anywhere and rent processing

power and software from anywhere

on the Net

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside web applications6

Our customers are moving atInternet speed. They need us to respond at Internet speed.

—Laurie Tucker, Federal Express vice president

Computer Confluence 7/e Chapter 9 Inside Web Applications

Intranets, Extranets, and Electronic Commerce

Intranets: self-contained intra-organizational networks that offer e-mail, newsgroups, file transfer, Web publishing, and other Internet-like services

Firewallsprevent unauthorized communication and secure sensitive internal data

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside web applications7

Computer Confluence 7/e Chapter 9 Inside Web Applications

Extranets: private TCP/IP networks designed for outside use by customers, clients, and business partners of the organization which owns the extranet

Electronic data interchange (EDI): a decade-old set of specifications for ordering, billing, and paying for parts and services over private networks

Electronic commerce involves business transactions through electronic networks

Business-to-business (B2B) e-commerce: transactions that involve businesses providing goods or services to other businesses

Business-to-consumer (B2C) e-commerce: transactions that take place on the Internet because consumers don’t have access to an extranet

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 inside web applications8

Computer Confluence 7/e Chapter 9 Inside Web Applications

Web Services

Web services involve new kinds of Web-based applications that can be assembled quickly using existing software components

Examples:

Plug a shopping cart component into an

existing Web site

Design applications that can be accessed through a variety of Web-enabled devices

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 the evolving internet

Computer Confluence 7/e Chapter 9 The Evolving Internet

Internet2 and the Next Generation Internet

Internet2 was launched by the government and various corporations in 1998 to provide faster network communications for universities and research institutions

Next Generation Internet (NGI) will consist of a nationwide web of optical fiber integrated with intelligent management software to maintain high-speed connections

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 the evolving internet1

Computer Confluence 7/e Chapter 9 The Evolving Internet

Internet Issues: Ethical and Political Dilemmas

Filtering software to combat inappropriate content

Digital cash to make online transactionseasier and safer

Encryption software to prevent creditcard theft

Digital signatures to prevent e-mail forgery

Access and Censorship

The Digital Divide

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 the evolving internet2

Computer Confluence 7/e Chapter 9 The Evolving Internet

Cyberspace: The Electronic Frontier

Science fiction writers suggest that tomorrow’s networks will take us beyond the Internet into an artificial reality that has come to be known as cyberspace

Today’s computer networks are still light years from these futuristic visions

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 the evolving internet3

Computer Confluence 7/e Chapter 9 The Evolving Internet

Inventing the Future: The Invisible Information Infrastructure

Vint Cerf, one of the Internet’s founders, thinks the Internet is headed for space–the InterPlaNet project

Tim Berners-Lee, the inventor of the Web, is planning a Semantic Web, a Web full of data that is meaningful to computers as well as humans

A variety of Internet appliances, network computers, set-top boxes, PDAs, mobile phones, and other devices connected to the Internet in offices and homes

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 lesson summary

Computer Confluence 7/eChapter 9Lesson Summary

The Internet is a network of networks that connects all kinds of computers around the globe and uses standard protocols to allow Internet communication to occur

No single organization owns or controls the Internet

You can connect to the Internet in several ways that provide different degrees of access to Internet services

Most Internet applications are based on the client/server model

The Web uses a set of protocols to make a variety of Internet services and multimedia documents available to users through a simple point-and-click interface

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 lesson summary continued

Computer Confluence 7/e Chapter 9Lesson Summary (continued)

In addition to Web sites, a variety of applications are built on the protocols of the Internet and the Web. For example, people who use the Web depend on search engines to find the information they need

Peer-to-peer computing was popularized by music sharing services, but its applications go beyond music sharing

Many businesses are exploring ways to apply P2P technology

Grid computing goes beyond P2P computing by enabling people to share processor power

E-commerce is built on Internet technology

© 2006 Prentice-Hall, Inc.


Computer confluence 7 e chapter 9 lesson summary continued1

Computer Confluence 7/e Chapter 9Lesson Summary (continued)

Businesses use the Internet and the Web for business-to-business and business-to-customer communication

Many businesses have private networks, called intranets, based on Internet technology

Extranets are also private networks, based on the same technology that enables businesses to connect with their partners

As the Internet grows and changes, issues of privacy, security, censorship, criminal activity, universal access, and appropriate Net behavior are surfacing

© 2006 Prentice-Hall, Inc.


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