Transcript ppt_11
Chapter 11 From Internet to Information Infrastructure 2002 Prentice Hall Internet Applications: Communication and Connection 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 meta-search – conduct parallel searches using several different search engines and directories 2002 Prentice Hall 2 Search Engines Some search engines use keywords and Boolean logic to conduct searches 2002 Prentice Hall 3 Search Engines Other search engines allow searches by using a hierarchical directory or subject tree 2002 Prentice Hall 4 Portals Web entry stations that offer quick and easy access to a variety of services. Consumer portals includes 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 2002 Prentice Hall 5 Email on the Internet What appears on the screen depends on the type of Internet connection you have and the mail program you use. Popular graphical email programs include Eudora, Outlook and Netscape Communicator. 2002 Prentice Hall 6 Email on the Internet Email formats include: ASCII text--can be viewed by any mail client program HTML--displays text formatting, pictures, and links to Web pages 2002 Prentice Hall 7 Mailing Lists & Network News Mailing lists allow you to participate in email discussion groups on special-interest topics. A newsgroup is a public discussion on a particular subject consisting of notes written to a central Internet site and redistributed through a worldwide newsgroup network called Usenet 2002 Prentice Hall 8 Real-Time Communication Users are logged in at the same time. Instant Messaging for exchanging instant messages with on-line friends and co-workers Internet telephony (IP telephony) for long-distance toll-free telephone service Videoconferencing for two-way meetings 2002 Prentice Hall 9 Rules of Thumb: Netiquette Say what you mean and say it with care. Keep it short and to the point. Proofread yours messages. Learn the “nonverbal” language of the Net. Keep your cool. Don’t be a source of spam (Internet junk mail). Lurk before you leap. Check your FAQs. Give something back. 2002 Prentice Hall 10 Emoticons :) Happy person :( Sad person :-) Happy person with a nose :-( Sad person with a nose ;-) Person winking :-D Person laughing :-| Person feeling so-so :-o Shocked person Bizarre Emoticons >8-O-(&) Person just realizing that he or she has a tapeworm :---( Person who is sad because he or she has a large nose .-) Person who can still smile despite losing an eyeball ~oE]:-| Fisherperson heading for market with a basket on his or her head containing a three-legged octopus that is giving off smell rays http://www.randomhouse.com/features/davebarry/emoticon.html 2002 Prentice Hall 11 Push Technology The Web was built with pull technology—browsers on client computers “pull” information from server machines. Browser asks for information With push technology, information is delivered automatically to the client computer. New product descriptions Automatic software upgrades Updated news 2002 Prentice Hall 12 Peer-to-Peer and Grid Computing Peer-to-Peer (P2P) computing - users share music, movies, and other files without going through a central directory. Grid computing - anyone can plug in from anywhere and rent processing power and software from anywhere on the Net 2002 Prentice Hall 13 Intranets, Extranets and Electronic Commerce Intranets are self-contained intra-organizational networks that offer email, newsgroups, file transfer, Web publishing and other Internet-like services. Firewalls prevent unauthorized communication and secure sensitive internal data 2002 Prentice Hall 14 Intranets, Extranets and Electronic Commerce Extranets are private TCP/IP networks designed for outside use by customers, clients and business partners of the organization. electronic data interchange (EDI) - a decade-old set of specifications for ordering, billing, and paying for parts and services over private networks 2002 Prentice Hall 15 Intranets, Extranets and Electronic Commerce Electronic commerce involves business transactions through electronic networks. Business-to-business (B2B) e-commerce - transactions that involve businesses providing goods or services to other businesses Business-to-consumer (B2C) e-commerce - transactions that take place on the Internet, rather than an extranet, because consumers don’t have access to private extranets 2002 Prentice Hall 16 Web Services Web services involve new kinds of Web-based applications that can be assembled quickly using existing software components Examples: plug a shopping-cart component into an existing Web site design applications that can be accessed through a variety of Web-enabled devices 2002 Prentice Hall 17 The Evolving Internet Internet2 launched by the government and various corporations in 1998 to provide faster network communications for universities and research institutions. Next Generation Internet (NGI), will consist of a nationwide web of optical fiber integrated with intelligent management software to maintain highspeed connections. 2002 Prentice Hall 18 Internet Issues: Ethical and Political Dilemmas Filtering software to combat inappropriate content Digital cash to make on-line transactions easier and safer Encryption software to prevent credit card theft Digital signatures to prevent email forgery 2002 Prentice Hall 19 Internet Everywhere: The Invisible Information Infrastructure Blurring of the boundaries between the Web and interpersonal communication applications A variety of Internet appliances, network computers, set-top boxes, PDAs, mobile phones, and other devices connected to the Internet in offices and homes “In the future, everything with a digital heartbeat will be connected to the Internet.” Scott McNealy, CEO of Sun Microsystems 2002 Prentice Hall 20 2002 Prentice Hall 21