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تقنيات االنترنت Chapter 2 © 2009 Prentice-Hall, Inc. 1 Internet Communications Examples: 1. Instant Messaging 2. Podcasts 3. Webcasts 4. Wikis 5. Voice over Internet (VoIP) 6. E-mail © 2009 Prentice-Hall, Inc. 3 لالختبار حفظ تعداد 2 Internet Communications • Group communication Example 1. 2. 3. 4. 5. Social network Multiplayer online games Chat rooms Newsgroups Listservs © 2009 Prentice-Hall, Inc. لالختبار حفظ تعداد3 3 Instant Messaging 1. Real-time textbased conversations 2. Contacts must be online © 2009 Prentice-Hall, Inc. 4 Podcasts • Podcasts: Compressed audio/video files distributed on the Internet © 2009 Prentice-Hall, Inc. 5 Webcasts and Wikis • Webcast: Broadcast of audio/visual content over the Internet – Not updated automatically – Use streaming media • Wiki: Web site that allows anyone to change its content – provide source for collaborative writing © 2009 Prentice-Hall, Inc. 6 Voice over Internet Protocol (VOIP) 1. VoIP: Using the Internet to place phone calls 2. send voice data digitally 3. Requires a microphone, an Internet connection, and a VoIP provider © 2009 Prentice-Hall, Inc. 7 E-mail • Electronic mail • E-mail accounts – Client-based – Web-based © 2009 Prentice-Hall, Inc. 8 Social Networks • Social networks: online personal networks Ex. Facebook.com • Members share common interests • Members communicate by voice, chat, IM, video, and blogs • Members create personalized profiles © 2009 Prentice-Hall, Inc. 9 Chat Rooms • Real-time text-based conversations • Identity protection – Username © 2009 Prentice-Hall, Inc. 10 Newsgroups and Listservs • Newsgroups – Online discussion forums – Members post and reply to messages – Create or respond to “threads” • Listservs – Electronic mailing lists of e-mail addresses of people interested in a topic – Threads are sent as e-mails – Less public than newsgroups © 2009 Prentice-Hall, Inc. 11 Web Entertainment • Multimedia: – Involves forms of media and text • Graphics • Audio • Video © 2009 Prentice-Hall, Inc. 12 Navigating the Web: Web Browsers • • • • Computer software Graphical Enables Web navigation Popular browsers: – Internet Explorer, Firefox, safari © 2009 Prentice-Hall, Inc. 13 Web includes: 1. Web sites 2. URLs 3. Hyperlinks © 2009 Prentice-Hall, Inc. 14 Web Sites • Web site: – Collection of related Web pages – First page known as Home or Index page • Web page: – HTML document • Text and graphics – Unique address – Hyperlinks © 2009 Prentice-Hall, Inc. 15 URLs • URL: (Uniform Resource Locator) URL © 2009 Prentice-Hall, Inc. 16 Hyperlinks © 2009 Prentice-Hall, Inc. 17 Clients and Servers • The Internet is a client/server network • Client computer: – Users connected to the Internet – Requests data and Web pages • Server computer: – Stores Web pages and data – Returns the requested data to the client • IP addresses © 2009 Prentice-Hall, Inc. 18 Connecting to the Internet • Dial-up connections • Broadband connections – Cable – Satellite – DSL © 2009 Prentice-Hall, Inc. 19 Broadband Connections • Cable – Uses coaxial cable and a cable modem – Fast connection speed – Speed depends on number of users – Not available in all areas Coaxial cable © 2009 Prentice-Hall, Inc. 20 Broadband Connections • Digital Subscriber Line (DSL) – Uses telephone lines – Faster than dial-up – Doesn’t tie up line – Requires special DSL modem © 2009 Prentice-Hall, Inc. 21 Broadband Connections • Fiber optic Internet – Sends light through fiber optics – Fast – Expensive – Only available in certain areas © 2009 Prentice-Hall, Inc. 22 Broadband Connections • Satellite – Uses a satellite dish and coaxial cable – Almost anyone in the U.S. can receive satellite service – Signal is affected by location and weather © 2009 Prentice-Hall, Inc. 23 Dial-Up Connections • Uses standard telephone line • Requires a modem to convert analog and digital signals • Slowest connection speed (56K) © 2009 Prentice-Hall, Inc. 24 The Origin of the Internet • ARPANET (Advanced Research Projects Agency Network) © 2009 Prentice-Hall, Inc. 25 The Web vs. the Internet • The Web is part of the Internet distinguished by: – TCP/IP – HTML – hyperlinks © 2009 Prentice-Hall, Inc. 26