IntroductiontointernetresourceTheInternetisthelargestrepositoryofinformationwhichcanprovideveryverylargenetwork.Internetresourcescoveringvariousareas.Now,theInternetisbecomingmoreandmoreimportantinourdailylivesandmakesourlivesmorecomfortableandbetter.WhatcanInternetdoforus?Internethasfourmainapplicationsasfollows:l.E－mail.WithInternet,peoplecancompose,send,andreceiveelectronicmails.Manypeoplegetdozensofmessagesadayandconsideritastheirprimarywayofinteractingwiththeoutsideworld,faroutdistancingthetelephoneandsnailmail.2.News.Newsgroupsarespecialziedforumsinwhichuserswithacommoninterestcanexchagnemessages.ThousandsofnewsgroupsexistonInternet,ontechnicalandnontechnicaltopics,includingcomputers,science,ecreation,andpolitics.3.Remotelogin.UsingtheTelnet,Rlogin,orotherprograms,theuseranywhereonInternetcanlogintoanyothermachineonwhichhehasanaccount.4.Filetransfer.UsingtheFTPprogram,itispossibletocopyfilesfromonemachineonInternettoanother.Vastnumbersofarticles,databases,andotherinformationareavailableinthisway.TheNetworkComputerThenetworkcomputer,alsoknownastheInternettoaster,InternetapplianceorInternetdevice,isthelowcost,nomaintenancedesktopdevice.ItallowsuserstoeffortlesslyconnecttoInternetandnetworkresources.Fromthere,theycanshareanyresourceandperformallcomputingtasksthattheycurrentlydoontheirPCs.Thenetworkcomputerofferssimplicity.StrippedofthehardwareandsoftwarethatcomplicatethePClifeandonlycapableofnetworkaccessanddisplay,thenetworkcomputerreliesonthenetworkforvirtuallyallsoftware,services,processing,data,andresources.Iteliminatesthecontinuouscycleofdesktophardwareandsoftwareupgrades,pushingthatburdeninsteadontothenetwork.Needthelatestwordprocessororspreadsheet?Runitofftheserver,Wanttosaveyourwork?Justsenditofftothenetwork,whereitwillbestoredsecured,andbackedup.Firewall:aMeasureofNetworkSecurityWiththepopularityofInternet,itisincreasinglydifficulttoguaranteethenetworksecurity.Sometimesthenetworkwasbreachedbecauseofnotonlyhackers'visitbutalsoauthorizedusers'c