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1、ComputernetworkAcomputernetwork,oftensimplyreferredtoasanetwork,isacollectionofcomputersanddevicesinterconnectedbycommunicationschannelsthatfacilitatecommunicationsamongusersandallowsuserstoshareresources.Networksmaybeclassifiedaccordingtoawidevariet
2、yofcharacteristics.Acomputernetworkallowssharingofresourcesandinformationamonginterconnecteddevices.Contents[hide]·1History·2Purpose·3Networkclassificationo3.1Connectionmethodo3.2Wiredtechnologieso3.3Wirelesstechnologieso3.4Scaleo3.5Functionalrelatio
3、nship(networkarchitecture)o3.6Networktopology·4Typesofnetworksbasedonphysicalscopeo4.1Localareanetwork§4.1.1Personalareanetwork§4.1.2Homeareanetworko4.2Wideareanetwork§4.2.1Campusnetworko4.3Metropolitanareanetwork§4.3.1Enterpriseprivatenetwork§4.3.2V
4、irtualprivatenetwork§4.3.3Internetworko4.4Backbonenetwork§4.4.1Globalareanetwork§4.4.2Internet§4.4.3Intranetsandextranets§4.4.4Overlaynetwork·5Basichardwarecomponentso5.1Networkinterfacecardso5.2Repeaterso5.3Bridgeso5.4Switcheso5.5Routerso5.6Firewall
5、s·6References·7FurtherreadingHistoryEarlynetworksofcommunicatingcomputersincludedthemilitaryradarsystemSemi-AutomaticGroundEnvironment(SAGE)anditsrelativethecommercialairlinereservationsystemSemi-AutomaticBusinessResearchEnvironment(SABRE),startedint
6、helate1950s.[1][2]Inthe1960s,theAdvancedResearchProjectsAgency(ARPA)startedfundingthedesignoftheAdvancedResearchProjectsAgencyNetwork(ARPANET)fortheUnitedStatesDepartmentofDefense.Developmentofthenetworkbeganin1969,basedondesignsdevelopedduringthe196
7、0s.[3]TheARPANETevolvedintothemodernInternet.PurposeComputernetworkscanbeusedforavarietyofpurposes:·Facilitatingcommunications.Usinganetwork,peoplecancommunicateefficientlyandeasilyviaemail,instantmessaging,chatrooms,telephone,videotelephonecalls,and
8、videoconferencing.·Sharinghardware.Inanetworkedenvironment,eachcomputeronanetworkmayaccessandusehardwareresourcesonthenetwork,suchasprintingadocumentonasharednetworkprinter.·Sharingfiles,data,andinformation.Inanetworkenvironment,authorizedusermayacce
