today’s topics chapter 2: internet and world wide web chapter 3: wired and wireless technology
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Today’s TopicsToday’s Topics
Chapter 2: Internet and World Wide WebChapter 2: Internet and World Wide Web Chapter 3: Wired and Wireless Chapter 3: Wired and Wireless
TechnologyTechnology
How the Internet WorksHow the Internet Works
Internet: a global computer networkInternet: a global computer network Interoperability: a key success to the Interoperability: a key success to the
InternetInternet Internet Service Provider (ISP): a Internet Service Provider (ISP): a
company that sells Internet accountscompany that sells Internet accounts Netzero, SBC, Charter, AT&T, VerizonNetzero, SBC, Charter, AT&T, Verizon
Online Service: a for-profit firm that Online Service: a for-profit firm that provides a proprietary network provides a proprietary network AOL, EarthLink, MSNAOL, EarthLink, MSN
Internet AccessesInternet Accesses
Dial-Up Access: slow, not reliable but lowest Dial-Up Access: slow, not reliable but lowest costcost
Digital Subscriber Line (DSL): medium, reliable Digital Subscriber Line (DSL): medium, reliable but high costbut high cost
Cable and Satellite Access: fast, reliable but Cable and Satellite Access: fast, reliable but high costhigh cost
Satellite Access: medium, reliable, but high costSatellite Access: medium, reliable, but high cost Network Access: fast, available, and usually free Network Access: fast, available, and usually free
to usersto users
World Wide WebWorld Wide Web
WWW: a portion of the Internet that WWW: a portion of the Internet that contains billions of documentscontains billions of documents
World Wide Web Consortium (W3C): an World Wide Web Consortium (W3C): an organization issuing standards related to organization issuing standards related to all aspects of the Weball aspects of the Web
Web Site: a location that is accessible Web Site: a location that is accessible from the Internet and makes web pages from the Internet and makes web pages availableavailable
World Wide WebWorld Wide Web
Web Page: any document on a Web site Web Page: any document on a Web site that includes text, graphics, sound, or that includes text, graphics, sound, or videovideo
Home Page or Index Page: a default page Home Page or Index Page: a default page that is displayed automatically when that is displayed automatically when entering a site at the top levelentering a site at the top level
Hypertext: a method of preparing and Hypertext: a method of preparing and publishing text that is suited to be read publishing text that is suited to be read with a computerwith a computer
World Wide WebWorld Wide Web
Hyperlink or Link: a word that can be Hyperlink or Link: a word that can be clicked to bring another document into clicked to bring another document into viewview
Distribute Hypermedia System: a network-Distribute Hypermedia System: a network-based content development system that based content development system that uses multimedia resources as a mean of uses multimedia resources as a mean of navigation or illustrationnavigation or illustration
Dead or Broken Link: a link to documents Dead or Broken Link: a link to documents that have disappearedthat have disappeared
World Wide WebWorld Wide Web
Web Browser: a program that displays a Web Web Browser: a program that displays a Web documentdocument IE, Netscape Navigator, MosaicIE, Netscape Navigator, Mosaic
Uniform Resource Locator (URL): a string of Uniform Resource Locator (URL): a string of characters that precisely identifies an Internet characters that precisely identifies an Internet resource’s type and locationresource’s type and location ProtocolProtocol ServerServer PathPath Resource NameResource Name
URLURL
http://www.umsl.edu/current_students/index.htmlhttp://www.umsl.edu/current_students/index.html
URLURL
Hypertext Transfer Protocol (HTTP): the Hypertext Transfer Protocol (HTTP): the Internet standard that supports the Internet standard that supports the exchange of information on the Webexchange of information on the Web
Domain Name System (DNS): an Internet Domain Name System (DNS): an Internet address system that includes letters as address system that includes letters as well as numberswell as numbers
Domain Name Registration: a process for Domain Name Registration: a process for individuals and organizations to register a individuals and organizations to register a domain namedomain name
URLURL
Top-Level Domain (TLD) Name: the last Top-Level Domain (TLD) Name: the last part of the domain name that indicates the part of the domain name that indicates the type of organization in which the computer type of organization in which the computer is locatedis located .com, .edu, .gov, .org.com, .edu, .gov, .org
World Wide WebWorld Wide Web
Downloading: transferring a document or Downloading: transferring a document or file from another computer to your file from another computer to your computercomputer
Uploading: transferring a document or file Uploading: transferring a document or file from your computer to another computerfrom your computer to another computer
Finding Information on the WebFinding Information on the Web
Search Engine: a searching database that Search Engine: a searching database that claims to index the full Webclaims to index the full Web Google, MSN, Yahoo, AltaVistaGoogle, MSN, Yahoo, AltaVista
Specialized Search Engine: a searching Specialized Search Engine: a searching database to index specialized informationdatabase to index specialized information Careerbuilder, TravelocityCareerbuilder, Travelocity
Portal: a gateway that provides a conveniently Portal: a gateway that provides a conveniently organized subject guide to various Internet organized subject guide to various Internet contentcontent MSNMSN
Search TechniquesSearch Techniques
Search Operators: symbols or words used Search Operators: symbols or words used for advanced searchesfor advanced searches Inclusion and Exclusion Operators ( + and -)Inclusion and Exclusion Operators ( + and -) Wildcards (*)Wildcards (*) Phrase Searches (“ ”)Phrase Searches (“ ”) Boolean Searches (AND, OR and NOT)Boolean Searches (AND, OR and NOT) ParenthesesParentheses
Internet ServicesInternet Services
E-Mail: a software application to send and E-Mail: a software application to send and receive messages via networksreceive messages via networks
E-Mail Attachment: any computer file that is E-Mail Attachment: any computer file that is included with an e-mail messageincluded with an e-mail message
E-Mail Address: a unique cyberspace identity for E-Mail Address: a unique cyberspace identity for a particular recipient composed of a user name, a particular recipient composed of a user name, @ sign, name of the server hosting the e-mail @ sign, name of the server hosting the e-mail service, and the top level domainservice, and the top level domain
Spam: an unsolicited e-mail advertisingSpam: an unsolicited e-mail advertising
Internet ServicesInternet Services
Instant Messaging (IM) System: a system Instant Messaging (IM) System: a system that allows Internet users to exchange that allows Internet users to exchange near real-time messagesnear real-time messages
Internet Relay Chat (IRC): an Internet Internet Relay Chat (IRC): an Internet service that allows Internet users to join service that allows Internet users to join chat groups, using text-based chat groups, using text-based conversationconversation
File Transfer Protocol (FTP): a way that File Transfer Protocol (FTP): a way that files can be transferred over the Internetfiles can be transferred over the Internet
Internet ServicesInternet Services
Usenet: a worldwide computer-based Usenet: a worldwide computer-based discussion systemdiscussion system
Newsgroups: discussion groups devoted Newsgroups: discussion groups devoted to a single topicto a single topic
Listserv: electronic mailing listListserv: electronic mailing list
CommunicationsCommunications
Communication: process of electronically Communication: process of electronically sending and receiving messages between sending and receiving messages between two pointstwo points
Communication Channel: path through Communication Channel: path through which messages are passed from one which messages are passed from one location to the nextlocation to the next
- analog signal: phone- analog signal: phone
- digital signal : computer- digital signal : computer
CommunicationsCommunications
Bandwidth: amount of data that can be Bandwidth: amount of data that can be transmitted through a given communication transmitted through a given communication channel, measured in bits per second (bps)channel, measured in bits per second (bps)
Broadband: any transmission medium that Broadband: any transmission medium that transports high volumes of data at high speedstransports high volumes of data at high speeds
Modem: communications device used to Modem: communications device used to transmit data over telephone linestransmit data over telephone lines MoModulation: transformation from digital to analogdulation: transformation from digital to analog DemDemodulation: transformation from analog to digitalodulation: transformation from analog to digital
Transmission MediaTransmission Media
Wired MediaWired Media Twisted PairTwisted Pair Coaxial CableCoaxial Cable Fiber-Optic CableFiber-Optic Cable
Wireless MediaWireless Media InfraredInfrared RadioRadio BluetoothBluetooth MicrowavesMicrowaves SatellitesSatellites
Wired CommunicationWired Communication
Public Switched Telephone Network Public Switched Telephone Network (PSTN): global telephone system(PSTN): global telephone system
Last-Mile Problem: inability of home and Last-Mile Problem: inability of home and businesses to access the PSTN’s high-businesses to access the PSTN’s high-speed fiber-optic cables, along with speed fiber-optic cables, along with bottleneck of data on the last mile of bottleneck of data on the last mile of phone lines connecting homes and phone lines connecting homes and businessesbusinesses
Last-Mile TechnologiesLast-Mile Technologies
Integrated Services Digital Network (ISDN)Integrated Services Digital Network (ISDN) Digital Subscriber Line (DSL)Digital Subscriber Line (DSL) Coaxial Cable and Cable ModemsCoaxial Cable and Cable Modems Leased Lines: T1, T2, T3Leased Lines: T1, T2, T3 Synchronous Optical Network (SONET)Synchronous Optical Network (SONET)
ConvergenceConvergence
Convergence: merging of disparate Convergence: merging of disparate objects into new combinationsobjects into new combinations 1G: Analog Cellular Phone1G: Analog Cellular Phone 2G: Personal Communication Service (PCS)2G: Personal Communication Service (PCS)
• Digital Cellular PhoneDigital Cellular Phone• Web-Based Device: PDA (Palm Pilot, Blackberry, Web-Based Device: PDA (Palm Pilot, Blackberry,
etc.)etc.)