Internet的发展历史 中英文.docx

Internet的发展历史 中英文.docx

《Internet的发展历史 中英文.docx》由会员分享，可在线阅读，更多相关《Internet的发展历史 中英文.docx（10页珍藏版）》请在冰豆网上搜索。

Internet的发展历史中英文

TheHistoryoftheInternet

TheBeginning-ARPAnet

TheInternetstartedasaprojectbytheUSgovernment.Theobjectoftheprojectwastocreateameansofcommunicationsbetweenlongdistancepoints,intheeventofanationwideemergencyor,morespecifically,nuclearwar.TheprojectwascalledARPAnet,anditiswhattheInternetstartedas.Fundedspecificallyformilitarycommunication,theengineersresponsibleforARPANethadnoideaofthepossibilitiesofan"Internet."

Bydefinition,an'Internet'isfourormorecomputersconnectedbyanetwork.

ARPAnetachieveditsnetworkbyusingaprotocolcalledTCP/IP.Thebasicsaroundthisprotocolwasthatifinformationsentoveranetworkfailedtogetthroughononeroute,itwouldfindanotherroutetoworkwith,aswellasestablishingameansforonecomputerto"talk"toanothercomputer,regardlessofwhetheritwasaPCoraMacintosh.

Bythe80'sARPAnet,justyearsawayfrombecomingthemorewellknownInternet,had200computers.TheDefenseDepartment,satisfiedwithARPAnetsresults,decidedtofullyadoptitintoservice,andconnectedmanymilitarycomputersandresourcesintothenetwork.ARPAnetthenhad562computersonitsnetwork.Bytheyear1984,ithadover1000computersonitsnetwork.

In1986ARPAnet（supposedly）shutdown,butonlytheorganizationshut

down,andtheexistingnetworksstillexistedbetweenthemorethan1000

computers.ItshutdownduetoafailiedlinkupwithNSF,whowantedto

connectits5countywidesupercomputersintoARPAnet.

WiththefundingofNSF,newhighspeedlinesweresuccessfullyinstalled

atlinespeedsof56k（anormalmodemnowadays）throughtelephonelines

in1988.Bythattime,therewere28,174computersonthe（bythendecided）Internet.In1989therewere80,000computersonit.By1989,therewere290,000.

Anothernetworkwasbuilttosupporttheincrediblenumberofpeople

joining.Itwasconstructedin1992.

Today-TheInternet

Today,theInternethasbecomeoneofthemostimportanttechnologicaladvancementsinthehistoryofhumanity.Everyonewantstoget'online'toexperiencethewealthofinformationoftheInternet.MillionsofpeoplenowusetheInternet,andit'spredictedthatbytheyear2003everysinglepersonontheplanetwillhaveInternetaccess.TheInternethastrulybecomeawayoflifeinourtimeandera,andisevolvingsoquicklyitshardtodeterminewhereitwillgonext,ascomputerandnetworktechnologyimproveeveryday.

HOWITWORKS:

It'sastandardthing.PeopleusingtheInternet.Shopping,playinggames,conversinginvirtualInternetenvironments.

TheInternetisnota'thing'itself.TheInternetcannotjust"crash."Itfunctionsthesamewayasthetelephonesystem,onlythereisnoInternetcompanythatrunstheInternet.

TheInternetisacollectionofmillioinsofcomputersthatareallconnectedtoeachother,orhavethemeanstoconnecttoeachother.TheInternetisjustlikeanofficenetwork,onlyithasmillionsofcomputersconnectedtoit.

ThemainthingabouthowtheInternetworksiscommunication.HowdoesacomputerinHoustonknowhowtoaccessdataonacomputerinTokyotoviewawebpage?

Internetcommunication,communicationamongcomputersconnectedtotheInternet,isbasedonalanguage.ThislanguageiscalledTCP/IP.TCP/IPestablishesalanguageforacomputertoaccessandtransmitdataovertheInternetsystem.

ButTCP/IPassumesthatthereisaphysicalconnecetionbetweenonecomputerandanother.Thisisnotusuallythecase.TherewouldhavetobeanetworkwirethatwenttoeverycomputerconnectedtotheInternet,butthatwouldmaketheInternetimpossibletoaccess.

Thephysicalconnectionthatisrequireedisestablishedbywayofmodems,phonelines,andothermodemcableconnections（likecablemodemsorDSL）.Modemsoncomputersreadandtransmitdataoverestablishedlines,whichcouldbephonelinesordatalines.Theactualhardcoreconnectionsareestablishedamongcomputerscalledrouters.

Arouterisacomputerthatservesasatrafficcontrollerforinformation.

Toexplainthisbetter,let'slookathowastandardcomputermightviewawebpage.

1.Theuser'scomputerdialsintoanInternetServiceProvider（ISP）.TheISPmightinturnbeconnectedtoanotherISP,orastraightconnectionintotheInternetbackbone.

2.TheuserlaunchesawebbrowserlikeNetscapeorInternetExplorerandtypesinaninternetlocationtogoto.

3.Here'swherethetrickypartcomesin.First,thecomputersendsdataaboutit'sdatarequesttoarouter.Arouterisaveryhighspeedpowerfulcomputerrunningspecialsoftware.Thecollectionofroutersintheworldmakewhatiscalleda"backbone,"onwhichallthedataontheInternetistransferred.Thebackbonepresentlyoperatesataspeedofseveralgigabytesper-second.Suchaspeedcomparedtoanormalmodemislikecomparingtheheatofthesuntotheheatofanice-cube.

Routershandledatathatisgoingbackandforth.Arouterputssmallchunksofdataintopackagescalledpackets,whichfunctionsimilarlytoenvelopes.So,whentherequestforthewebpagegoesthrough,itusesTCP/IPprotocolstotelltherouterwhattodowiththedata,whereit'sgoing,andoverallwheretheuserwantstogo.

4.Theroutersendsthesepacketstootherrouters,eventuallyleadingtothetargetcomputer.It'slikewhisperdownthelane（onlytheinformationremainsintact）.

5.Whentheinformationreachesthetargetwebserver,thewebserverthenbeginstosendthewebpageback.Awebserveristhecomputerwherethewebpageisstoredthatisrunningaprogramthathandlesrequestsforthewebpageandsendsthewebpagetowhoeverwantstoseeit.

6.Thewebpageisputinpackets,sentthroughrouters,andarriveattheuserscomputerwheretheusercanviewthewebpageonceitisassembled.

Thepacketswhichcontainthedataalsocontainspecialinformationthatletsroutersandothercomputersknowhowtoreassemblethedataintherightorder.

Withmillionsofwebpages,andmillionsofusers,usingtheInternetisnotalwayseasyforabeginninguser,especiallyforsomeonewhoisnotentirelycomfortalewithusingcomputers.BelowyoucanfindtipstricksandhelponhowtousemainservicesoftheInternet.

Beforeyouaccesswebpages,youmusthaveawebbrowsertoactuallybeabletoviewthewebpages.MostInternetAccessProvidersprovideyouwithawebbrowserinthesoftwaretheyusuallygivetocustomers;you.Thefactthatyouareviewingthispagemeansthatyouhaveawebbrowser.ThetoptwousebrowsersareNetscapeCommunicatorandMicrosoftInternetExplorer.NetscapecanbefoundatandMSIEcanbefoundat

Thefactthatyou'rereadingthisrightnowmeansthatyouhaveawebbrowser.

Nextyoumustbefamiliarwithactuallyusingwebpages.Awebpageisacollectionofhyperlinks,images,text,forms,menus,andmultimedia.To"navigate"awebpage,simplyclickthelinksitprovidesorfollowit'sowninstructions（likeifithasaformyouneedtouse,itwillprobablyinstructyouhowtouseit）.Basically,everythingaboutawebpageismadetobeself-explanetory.Thatisthenatureofawebpage,tobeeasilynavigatable.

"Ohno!

a404error!

'Cannotfindwebpage?

'"isacommonremarkmadebynewweb-users.

Sometimeswebsiteshaveerrors.Butanerroronawebsiteisnottheuser'sfault,ofcourse.

A404errormeansthatthepageyoutriedtogotodoesnotexist.Thiscouldbebecausethesiteisstillbeingconstructedandthepagehasn'tbeencreatedyet,orbecausethesiteauthormadeatypointhepage.There'snothingmuchtodoabouta404errorexceptfore-mailingthesiteadministrator（ofthepageyouwantedtogoto）antellinghim/herabouttheerror.

AJavascripterroristheresultofaprogrammingerrorintheJavascriptcodeofawebsite.NotallwebsitesutilizeJavascript,butmanydo.JavascriptisdifferentfromJava,andmostbrowsersnowsupportforexample）,youmightgetJavascripterrorsbecausesitesutilizeJavascriptversionsthatyourbrowserdoesnotsupport.So,youcantrygettinganewerversionofyourwebbrowser.

E-mailstandsforElectronicMail,andthat'swhatitis.E-mailenablespeopletosendletters,andevenfilesandpicturestoeachother.

Tousee-mail,youmusthaveane-mailclient,whichisjustlikeapersonalpostoffice,sinceitretrievesandstorese-mail.

Secondly,youmusthaveane-mailaccount.MostInternetServiceProvidersprovidefreee-mailaccount（s）forfree.Someservicesofferfreee-mail,likeHotmail,andGeocities.

Afterconfiguringyoure-mailclientwithyourPOP3andSMTPserveraddress（youre-mailproviderwillgiveyouthatinformation）,youarereadytoreceivemail.

Anattachmentisafilesentinaletter.Ifsomeonesendsyouanattachmentandyoudon'tknowwhoitis,don'trunthefile,ever.Itcouldbeavirusorsomeotherkindofnastyprograms.Youcan'tgetavirusjustbyreadinge-mail,you'llhavetophysicallyexecutesomeformofprogramforavirustostrike.

Asignatureisafeatureofmanye-mailprograms.Asignatureisaddedtotheendofeverye-mailyousendout.Youcanputatextgraphic,yourbusinessinformation,anythingyouwant.

ImaginethatacomputerontheInternetisanislandinthesea.Theseaisfilledwithmillionsofislands.ThisistheInternet.Imagineanislandcommunicateswithotherislandbysendingshipstootherislandsandreceivingships.Theislandhasportstoacceptandsendoutships.

AcomputerontheInternethasaccessnodescalledports.Aportisjustasymbolicobjectthatallowsthecomputertooperateonanetwork（ortheInternet）.Thismethodissimilartotheisland/oceansymbolismabove.

Telnet