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
© 2008 Prentice-Hall, Inc.
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.
© 2008 Prentice-Hall, Inc.
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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.
© 2008 Prentice-Hall, Inc.
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Tomorrow’s Technology and You 8/e Chapter 9
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
© 2008 Prentice-Hall, Inc.
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Tomorrow’s Technology and You 8/e Chapter 9
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
© 2008 Prentice-Hall, Inc.
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Tomorrow’s Technology and You 8/e Chapter 9
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.
© 2008 Prentice-Hall, Inc.
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Tomorrow’s Technology and You 8/e Chapter 9
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.
© 2008 Prentice-Hall, Inc.
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Tomorrow’s Technology and You 8/e Chapter 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
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Tomorrow’s Technology and You 8/e Chapter 9
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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Tomorrow’s Technology and You 8/e Chapter 9
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
© 2008 Prentice-Hall, Inc.
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Tomorrow’s Technology and You 8/e Chapter 9
Inside the Internet
© 2008 Prentice-Hall, Inc.
User President whose mail is stored on the host whitehouse in the government domain
User hazel_filbert at the admin server for Grant MacEwan Community College in Alberta, Canada
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Tomorrow’s Technology and You 8/e Chapter 9
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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Tomorrow’s Technology and You 8/e Chapter 9
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
© 2008 Prentice-Hall, Inc.
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Tomorrow’s Technology and You 8/e Chapter 9
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.
© 2008 Prentice-Hall, Inc.
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Tomorrow’s Technology and You 8/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 computersFile compression saves storage space on disk and saves transmission time when
files are transferred through networks.
© 2008 Prentice-Hall, Inc.
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Tomorrow’s Technology and You 8/e Chapter 9
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.
© 2008 Prentice-Hall, Inc.
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Tomorrow’s Technology and You 8/e Chapter 9
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
© 2008 Prentice-Hall, Inc.
US.html
Protocol for Web pages
http:// weatherunderground.com/
Domain Name Resource File
satellite/vis/1k/
Path
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Tomorrow’s Technology and You 8/e Chapter 9
Inside the Web
© 2008 Prentice-Hall, Inc.
HTML is not WYSIWYG (What You See Is What You Get).
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Tomorrow’s Technology and You 8/e Chapter 9
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
© 2008 Prentice-Hall, Inc.
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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Tomorrow’s Technology and You 8/e Chapter 9
Inside the WebFrom Hypertext to Multimedia
Typical Web pages can contain:
© 2008 Prentice-Hall, Inc.
TablesFramesFormsAnimationsSearch Engines
Downloadable audio and video
Streaming audio and videoReal-time live
audio or video3-D environmentsPersonalization
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Tomorrow’s Technology and You 8/e Chapter 9
Inside the Web
Plug-ins and Helper Applications
© 2008 Prentice-Hall, Inc.
RealOneQuickTimeShockwave/FlashRealPlayerAdobe Reader and Acrobat
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Tomorrow’s Technology and You 8/e Chapter 9
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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Tomorrow’s Technology and You 8/e Chapter 9
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
© 2008 Prentice-Hall, Inc.
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Tomorrow’s Technology and You 8/e Chapter 9
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
© 2008 Prentice-Hall, Inc.
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Tomorrow’s Technology and You 8/e Chapter 9
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.
© 2008 Prentice-Hall, Inc.
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Tomorrow’s Technology and You 8/e Chapter 9
Inside the Web
Specialized Search Engines: Google Maps, Froogle, and others
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Tomorrow’s Technology and You 8/e Chapter 9
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.
© 2008 Prentice-Hall, Inc.
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Tomorrow’s Technology and You 8/e Chapter 9
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.
© 2008 Prentice-Hall, Inc.
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Tomorrow’s Technology and You 8/e Chapter 9
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.
© 2008 Prentice-Hall, Inc.
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Tomorrow’s Technology and You 8/e Chapter 9
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
© 2008 Prentice-Hall, Inc.
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Tomorrow’s Technology and You 8/e Chapter 9
The Evolving Internet
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.
© 2008 Prentice-Hall, Inc.
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Tomorrow’s Technology and You 8/e Chapter 9
The Evolving Internet
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.
© 2008 Prentice-Hall, Inc.
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Tomorrow’s Technology and You 8/e Chapter 9
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.
© 2008 Prentice-Hall, Inc.
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Tomorrow’s Technology and You 8/e Chapter 9
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.
© 2008 Prentice-Hall, Inc.
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Tomorrow’s Technology and You 8/e Chapter 9
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.
© 2008 Prentice-Hall, Inc.
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