Discovering Computers 2010

1. Discovering Computers 2010 Chapter 2The Internet and World Wide Web

2. The Internet Next • Also the Net • Worldwide collection of networks • Services on the Internet • Two of the Mostly widely used services • World Wide Web (WWW) • Email • Other services • Chat rooms • Instant Messaging • VoIP (Voice over Internet Protocol)

3. Evolution of the Internet ARPANET Networking project by Pentagon’s Advanced Research Projects Agency (ARPA) Goal:To allow scientists at different locations to share information Goal:To function if part of network were disabled Became functional September 1969 Next How did the Internet originate?

4. Evolution of the Internet Today More than 550 million host nodes 1984 More than 1,000 host nodes 1969 Four hostnodes (provide services and connection to others on a network (UCLA, UCSB, Stanford, Utah) Next How has the Internet grown?

5. Evolution of the Internet National Science Foundation (NSF) • In 1986 connected its huge network of five supercomputers (NSFnet) to ARPANET • Became known as the Internet • Until 1995, handle the bulk of the communication activity • In 1995, terminated its network on the Internet and resumed its status as a research network

6. Evolution of the Internet World Wide Web Consortium (W3C) • Oversees research, sets standards and guidelines • Mission is to contribute to the growth of the Web • Nearly 400 organizations around the world are members of the W3C Next Who controls the Internet? • No onec—cit is a public, cooperative, andindependent network • Several organizations set standards

7. Internet 2 • Not-for-Profit research and development project that connects universities and companies via a high –speed private network • Goals was to develop and test advanced network technologies that will benefit Internet users in the short-term future • Some projects that are now mainstream includes: • Telemedicine and digital libraries

8. How the Internet Works Next How can you connect to the Internet? Slow-speed technology High-speed connection Dial-up accessmodem in your computer uses a standard telephone line to connect to the Internet Broadband Internet service Cable, DSL, fiber, radio signals, and satellite Connection must be established each time you log on. Connection is always on—whenever the computer is running

9. Connecting to the Internet • DSL (digital subscriber line) – use the regular copper telephone lines • Fiber to the Premises(FTTP) – use fiber-optic cable • Fixed wireless – use dish-shaped antenna on the house or business • Cellular radio network – use built-in compatible technology or computers with wireless modems • Wi-Fi (wireless fidelity) – uses radio signals • Satellite Internet service – use satellite to satellite dish

10. How the Internet Works Next What are ways to access the Internet? • An access provider is a business that provides individual and organization access to the Internet free or for a fee. • Three Categories: • ISP, Regional or National (AT&T and EarthLink) • OSP (AOL and MSN, two more popular) • Wireless Internet Service Provider (ex. AT&T, Boingo Wireless, Sprint Broadband Direct, T-Mobile, and Verizon Wireless)

11. How the Internet Works Next What is a IP address? • Internet protocol address • Number that uniquely identifies each computer or device connected to Internet • Consists of four groups of numbers, each separated by a period • Number between 0 and 255 • The first portion of each IP address identifies the network and the last portion identifies the specific computer

12. How the Internet Works Next What is a domain name? • Text version ofInternet protocol(IP) address • The text in the domain name up to the first period identifies the type of Internet server. • The last section contains the top-level domain (identifies the type of organization) • ICANN – assigns and controls top-level domains

13. The World Wide Web A worldwide collection of electronic documents Also called the Web Each electronic document is called a Web page Emerged in the early 1990s Can contain text, graphics, audio, video, and built-in connections A Web site is a collection of related Web pages Next What is the World Wide Web (WWW)?

14. The World Wide Web InternetExplorer Google Chrome Firefox Opera Safari Next What is a Web browser? • Program that allows you to view Web pages • The more widely used Web browsers for PC are:

15. The World Wide Web Next What is a home page? • The first page that a Web site displays • Often provides linksto other documents, Web pages or Websites • A link, short for hyperlink, is built-in connection to another related Web page or part of a Web page

16. The World Wide Web Next How do Internet-enabled mobile devices access the Web? • Use a microbrowser that displays Web pages that contain mostly text

17. The World Wide Web Next What is downloading? • The process of a computer receiving information • Depending upon connection speed, downloading can take from a few seconds to several minutes

18. World Wide Web Next What is a URL? Unique address for a Web page • Consist of a protocol, domain name and sometimes the path to a specific Web page or location on a Web page. • Many web page addresses begin with http:// (a set of rules that defines how pages transfer on the Internet • Not required • A web server delivers the Web page to your computer

19. The World Wide Web How do you Navigate Web Pages? • Hypertext – refers to links in text-based documents • Hypermedia – combines text-based links with graphic, audio, and video links • Some people use the phrase, surfing the Web, to refer to the activity of using links to explore the Web. • Tabbed browsing – top of the browser displays a tab for each Web page you open.

20. The World Wide Web Next How can you recognize links? • Pointer changes to a small handwhen you point toa link • A link can be text or an image • Text links areusually underlinedand in a differentcolor

21. The World Wide Web How do you Search the Web? • Primary reason that people use the Web is to search for specific information. • There are two types of search tools • Search Engines • Subject Directories

22. The World Wide Web Next What is a search engine? • Program used to find Web sites and Web pages by entering words or phrases called search text • Each word in the search text is known as a keyword. • Hits are the results of an search.

23. The World Wide Web Next What is a subject directory? • Search tool with organized set of categories and subcategories • Lets you find information by clicking links rather than entering keywords • Major disadvantage is that users have difficulty deciding which categories to choose.

24. The World Wide Web • Portal • News • Informational • Blog • Wiki • Online Social Network • Educational • Entertainment • Advocacy • Web Application • Content Aggregator • Personal What are the thirteen basic types of Web sites?

25. The World Wide Web Next What is a portal? • A Web site that offers a variety of services from one, convenient location, usually for free • Searching, news, sports and weather, Web publishing, reference tools, stock quotes, maps, shopping, e-mail, and online communities(Web sites that join people with similar interests)

26. The World Wide Web Next What is a news Web site? • Contains newsworthy material • Stories and articles relating to current events, life, money, sports, and the weather

27. The World Wide Web Next What is an informational Web site? • Contains factual information • Created by organizations and government agencies

28. The World Wide Web Next What is a business/marketing Web site? • Contains content that promotes or sells products or services • Allows you to purchase products or services online

29. The World Wide Web Next What is a blog? • Short for Weblog • An informal website consisting of time-stamped articles or posts, in a diary or journal format • Uses a regularly updated journal format to reflect the interests, opinions, and personalities of the author and sometimes site visitors • Blogger – author of a blog

30. The World Wide Web What is a wiki? • Collaborative Web site that allows users to create, add to, modify, or delete the Web site content via their Web browser • Are open to modification by the general public • Difference between a wiki and blog is that users cannot modify original posts made by the blogger. • Popular wiki - Wikipedia

31. The World Wide Web Next What is an online social network? • Encourages members to share their interests, ideas, stories, photos, music, and videos • Popular social networking sites include Facebook and MySpace. • Media sharing Web site • Share photos, music, and videos

32. The World Wide Web Next What is an educational Web site? • Offers avenues for formal and informal teachingand learning • Learn how airplanesfly or how to cook ameal • Some colleges offer online classes and degrees

33. The World Wide Web Next What is an entertainment Web site? • Offers an interactive and engaging environment featuring music, videos, sports, games, ongoing Web episodes, sweepstakes, chats, and more

34. The World Wide Web Next What is an advocacy Web site? • Contains content that describes a cause, opinion,or idea

35. The World Wide Web Next What is an Web Application Web site? • Allows users to access and interact with software through a Web browser on any computer or device that is connected the Internet

36. The World Wide Web Next What is a content aggregator? • Business that gathers and organizes Web content and then distributes, or feeds, the content to subscribers for free or a fee

37. The World Wide Web Next What is a personal Web site? • Web page maintained by private individual or family • Reasons: sharing life experience with the worldor job hunting