1. © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Chapter 5A The Internet

2. 2 2 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Learning Objectives 5.1Describe two reasons for the Internet’s creation 5.2 Identify six major services you can access through the Internet 5.3 Explain how to use a browser, discuss ways to search for information, and list three types of social media programs or sites 5.4Identify how the Internet can be useful in a school or educational setting

3. 3 3 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Internet History Internet: a global communications system that links together thousands of networksInternet: a global communications system that links together thousands of networks ARPANET: a Defense Department network linking computers at universities and defense contractorsARPANET: a Defense Department network linking computers at universities and defense contractors NSFnet: A higher-capacity network created by the National Science Foundation (NSF)NSFnet: A higher-capacity network created by the National Science Foundation (NSF) Backbones: Central network structuresBackbones: Central network structures

4. 4 4 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Internet Services Connects thousands of networks and hundreds of millions of users around the worldConnects thousands of networks and hundreds of millions of users around the world No central ownership or controlNo central ownership or control –Guidelines and standards (e.g., the Internet Society, World Wide Web Consortium) –Free expression –Open to anyone who can access it

5. 5 5 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Internet Services Includes:Includes: –World Wide Web –Electronic mail –Chat and instant messaging –File transfer protocol –Peer-to-peer –Voice over Internet Protocol

6. 6 6 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. World Wide Web Created in 1989 at CERNCreated in 1989 at CERN Evolution of the WebEvolution of the Web –Web 1.0: from it’s creation through the early 2000s; the focus was on providing information –Web 2.0: from middle 2000s into around the middle 2010s; sites feature user-generated content –Web 3.0: The next phase of activity that is expected to occur

7. 7 7 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Electronic Mail A system for exchanging messages through a computer networkA system for exchanging messages through a computer network One of the first uses of the InternetOne of the first uses of the Internet Data files can be attachedData files can be attached Spam: unwanted messages that can be managed with filtering toolsSpam: unwanted messages that can be managed with filtering tools

8. 8 8 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Chat and Instant Messaging Chat: Communication in real time via softwareChat: Communication in real time via software –Internet Relay Chat (IRC): Early method of chat –Chat channels are typically created by topic Instant messaging (IM): A type of chat software that restricts participation to specific usersInstant messaging (IM): A type of chat software that restricts participation to specific users –Buddy list - list of other users with whom they want to chat –Software may be stand-alone or embedded in other programs

9. 9 9 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. File Transfer Protocol File transfer protocol (FTP): An Internet service that houses collections of files on an FTP serverFile transfer protocol (FTP): An Internet service that houses collections of files on an FTP server –Can be public –Files may be retrieved with a common Web browser or with client software –Files available on FTP sites include weather maps, downloadable software and program upgrades

10. 10 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Peer-to-Peer Peer-to-peer (P2P): File transfer design that uses a distributed network that does not require a central serverPeer-to-peer (P2P): File transfer design that uses a distributed network that does not require a central server –Software lets a user’s computer identify other computers in the distributed network and access them directly –Allow people to share files of all types directly –Used for both legitimate sharing and unauthorized copying of copyrighted works

11. 11 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Voice Over Internet Protocol Voice over Internet Protocol (VoIP) service: translates analog voice signals into digital data and uses the Internet to transport the dataVoice over Internet Protocol (VoIP) service: translates analog voice signals into digital data and uses the Internet to transport the data –Can connect to telephone networks and digital sources –Users can lease a telephone number in another country –Quality of VoIP calls depends on the quality of the network connection

12. 12 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. The Internet at Home Web browserWeb browser Search enginesSearch engines GamesGames Radio and televisionRadio and television Social media softwareSocial media software

13. 13 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Web Browser Software that enables users to access the World Wide WebSoftware that enables users to access the World Wide Web Web pages: Documents for Web browsersWeb pages: Documents for Web browsers –Hypertext: document text that links to other objects –HTML: contains instructions for browsers to interpret Hypertext links : Encoded words or pictures that, when clicked on, take the user to another locationHypertext links : Encoded words or pictures that, when clicked on, take the user to another location URLs: Format for hyperlinks that identifies each object on the Web and how it should be retrievedURLs: Format for hyperlinks that identifies each object on the Web and how it should be retrieved

14. 14 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Web Browser HTTP : defines the exact way in which data is formatted and transferred back and forth between browser and serverHTTP : defines the exact way in which data is formatted and transferred back and forth between browser and server –HTTP is not secure HTTPS : adds data encryption and Web site identity verificationHTTPS : adds data encryption and Web site identity verification –Secure Web sites obtain a digital certificate from a certificate authority

15. 15 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Search Engines and Games Search engines : a combination of hardware and software that constantly crawl through the Web’s contents, finding new informationSearch engines : a combination of hardware and software that constantly crawl through the Web’s contents, finding new information –Popular search engines include Google and Bing GamesGames –Thousands of games are available for modern PCs and game consoles –The Internet allows people to play with and against one another online

16. 16 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Radio and Television Many viewers can go online to watch their favorite showsMany viewers can go online to watch their favorite shows Radio channels, including local radio stations, also are available onlineRadio channels, including local radio stations, also are available online Many people create their own audio and video broadcasts and save them as online files, known as podcastsMany people create their own audio and video broadcasts and save them as online files, known as podcasts –available for download

17. 17 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Social Media Software Social media software: Programs and utilities that make it simple for people to share common interests and informationSocial media software: Programs and utilities that make it simple for people to share common interests and information –Social networking Web sites: designed to connect people directly –Anyone can create a personal information layout, or profile Twitter: specializes in the sharing of micro-status messages, called tweets, of up to 140 charactersTwitter: specializes in the sharing of micro-status messages, called tweets, of up to 140 characters

18. 18 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Internet at School An education helper:An education helper: –Edutainment programs: Software that attempts to be both educational and entertaining –Standardized testing via Web-based test programs Online researchOnline research Online classes and universitiesOnline classes and universities