Slide 1 Tomorrows Technology and You 8 th Edition © 2008 Prentice-Hall, Inc.

Slide 1

Tomorrow’s Technology and You

8th Edition

© 2008 Prentice-Hall, Inc.

Slide 2

Tomorrow’s Technology and You 8/e

Chapter 9

The Evolving Internet


Slide 3

Tomorrow’s Technology and You 8/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.


Slide 4

Tomorrow’s Technology and You 8/e Chapter 9

Objectives (continued)

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.


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ARPANET Pioneers Build a Reliable Network

Out of Unreliable Parts 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 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


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Inside the InternetCounting Connections

The Internet: an interconnected network of thousands of networks Links academic, research, government, and

commercial institutionsConnects computers to about every

country in the world Growing too fast to measure its growth Internet is decentralized Internet doesn’t have hard boundaries


Slide 7


Inside the Internet

Internet ProtocolsTransmission Control Protocol/Internet Protocol, TCP/IP…

At the heart of the Internet Allows cross-network communication

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. Packet-switching is flexible and robust.


Slide 8


Inside the Internet

Internet Protocols 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. NextGeneration Internet will allow more addresses and multicasting.


Slide 9


Inside the InternetInternet 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 organization sites


Slide 10


Inside the Internet

Internet Addresses .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


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Inside the InternetAn email address includes:

[email protected] 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


Slide 12


Inside the Internet


[email protected]

User President whose mail is stored on the host whitehouse in the government domain

[email protected]

User hazel_filbert at the admin server for Grant MacEwan Community College in Alberta, Canada

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Inside the Internet

Internet Access OptionsDirect (Dedicated) Connection

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

No need to dial upFiles are stored on your computerQuick response time

Dialup ConnectionLimited connection using a modemFull access dialup uses POTS or PPP via

modem


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Inside the Internet

Internet Access OptionsBroadband 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


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Inside the Internet

Internet Access Options 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. Online Services like AOL and MSN offer extra services.


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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 computersFile compression saves storage space on disk and saves transmission time when

files are transferred through networks.


Slide 17


Inside the Internet

Internet Servers 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.


Slide 18


Inside the Web

Web Protocols: HTTP and HTMLHTTP (Hypertext transfer protocol) used to transfer Web pages

HTML (HyperText Markup Language) created for encoding and displaying documents


US.html

Protocol for Web pages

http:// weatherunderground.com/

Domain Name Resource File

satellite/vis/1k/

Path

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Inside the Web


HTML is not WYSIWYG (What You See Is What You Get).

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Inside the WebPublishing on the Web

Programs that convert document format features into HTML codes: Microsoft Word, PowerPoint, FileMaker

Web authoring programs: Dreamweaver, GoLive, Microsoft FrontPage


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

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Inside the WebFrom Hypertext to Multimedia

Typical Web pages can contain:


TablesFramesFormsAnimationsSearch Engines

Downloadable audio and video

Streaming audio and videoReal-time live

audio or video3-D environmentsPersonalization

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Inside the Web

Plug-ins and Helper Applications


RealOneQuickTimeShockwave/FlashRealPlayerAdobe Reader and Acrobat

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Inside the Web

Dynamic Web Sites: Beyond HTML

Dynamic HTMLAdds more programming power to HTML by allowing code

to automatically modify itself under certain circumstances

Languages for dynamic sitesPerl scripting languageJava: Full-featured, cross-platform, object-oriented

programming language


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Inside the Web

Dynamic Web Sites: Beyond HTMLJava Applets: Small Java programs

Automatically downloaded onto 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 appletsWML (Wireless Markup Language)

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


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Inside the WebDynamic Web Sites: Beyond HTML

XML (Extensible Markup Language)Will replace HTML plus provide additional features and extensions

XHTMLA 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


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Inside the WebSearch Engines

Search engines are 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.


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Inside the Web

Specialized Search Engines: Google Maps, Froogle, and others


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Inside the Web Portals

Web entry stations that offer quick and easy access to a variety of services Consumer portals include search

engines,email 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.


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Inside the Web Push Technology: Notifications and Alerts

The Web was built with pull technology. Browsers on client computers “pull”

information from server machines. Essentially, the browser asks for information.

With push technology, information is delivered automatically to the client computer. New product descriptions Automatic software upgrades Updated news

RSS (Really Simple Syndication) pushes (feeds) information to people who read blogs.


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Inside the Web Peer-to-Peer and Grid Computing

Peer-to-Peer (P2P) ComputingUsers share music, movies, and other files without going

through a central directory. Use BitTorrent to download very large files.

Grid ComputingAnyone can plug in from anywhere and rent processing

power and software from anywhere on the Net.


Slide 31


Internet Issues: Ethical and Political Dilemmas

Internet Issues: Ethical and Political Dilemmas

Filtering software to combat inappropriate contentDigital cash to make online transactions

easier and saferEncryption software to prevent credit

card theft Digital signatures to prevent email forgeryAccess and censorshipThe digital divide


Slide 32



From Cyberspace to InfospherePaul McFedrie suggests that the Net today is like the

atmosphere—everywhere and necessary—and should be called our infosphere.

The Internet’s future depends on decisions we, as a society, make today.

The Net is evolving from a global community into a global intelligence.


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From Cyberspace to Infosphere

Kevin Kelly says the Internet “will evolve into an integral extension not only of our senses and bodies but our minds.”

In the Web, as in our brains, learning happens through ever-increasing interconnections.

As the Net changes, it changes our lives. Evolution of the Internet is far from over.


Slide 34


Lesson 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.


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Lesson Summary (continued)

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.

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.


Slide 36


Lesson Summary (continued)

Many businesses are exploring ways to apply P2P technology.

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

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


Slide 1 Tomorrows Technology and You 8 th Edition © 2008 Prentice-Hall, Inc.

Documents

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