IntroductiontoOperatingSystemsThispresentationwillexplorethefundamentalconceptsofoperatingsystems,theirevolution,andtheircrucialroleinmoderncomputing.WhatisanOperatingSystem?DefinitionAnoperatingsystem(OS)isasoftwareprogramthatmanagesacomputer'shardwareandsoftwareresources.PurposeItprovidesaplatformforapplicationstorunandallowsuserstointeractwiththecomputer.OperatingSystemFunctionsResourceManagementManagesCPU,memory,storage,andperipherals.ProcessManagementControlstheexecutionofprograms,allocatingresourcestoprocesses.UserInterfaceProvidesawayforuserstointeractwiththesystem.SecurityProtectssystemresourcesanddatafromunauthorizedaccess.CharacteristicsofOperatingSystemsConcurrencyAllowsmultipleprogramstorunsimultaneously.SharingEnablesresourcesharingamongmultipleusersorprograms.ProtectionProtectssystemresourcesfromunauthorizedaccess.EfficiencyOptimizesresourceutilizationtomaximizesystemperformance.TypesofOperatingSystemsBatchProcessesjobsinabatch,withoutuserinteraction.Time-SharingSharesCPUtimeamongmultipleusers,providinginteractiveaccess.Real-TimeRespondstoeventsinatimelymanner,oftenusedincriticalsystems.WindowProvidesagraphicaluserinterfacewithwindowsandicons.BatchProcessingOperatingSystems1EarlySystemsUsedinthe1950sand1960sfortaskslikedataprocessing.2NoUserInteractionJobswereprocessedinaqueue,withoutdirectuserinput.3ExampleEarlyIBMsystemsusedpunchedcardsforinput.Time-SharingOperatingSystems1InteractiveUseAllowmultipleuserstointeractwiththesystemsimultaneously.2MultitaskingEnablesmultipleprogramstorunconcurrentlyonasingleCPU.3ExamplesUnix,Multics,andearlyversionsofWindows.Real-TimeOperatingSystems(RTOS)1Time-CriticalMustrespondtoeventswithinspecifictimeconstraints.2ApplicationsUsedinindustrialcontrol,avionics,andmedicaldevices.3ExamplesVxWorks,QNX,andFreeRTOS.WindowOperatingSystems1GraphicalUserInterfaceProvideauser-friendlyvisualenvironment.2WindowsandIconsAllowuserstointeractwiththesystemusingwindowsandicons.3PopularExamplesWindows,macOS,andLinuxdesktopdistributions.NetworkOperatingSystemsResourceSharingEnablesharingoffiles,printers,andotherresourcesacrossanetwork.NetworkManagementProvidetoolsformanagingnetworkdevicesandusers.CommunicationProtocolsSupportvariouscommunicationprotocolsfordataexchange.DistributedOperatingSystemsEvolutionofOperatingSystems1EarlySystems(1940s-1950s)Batchprocessing,limitedmemory,andmanualoperation.2Single-UserSystems(1960s-1970s)Time-sharing,interactivecomputing,andmultiprogramming.3PersonalComputers(1980s-present)Graphicaluserinterfaces,multitasking,andnetworkconnectivity.EarlyOperatingSystemsLimitedFunctionalitySimpleprogramsthatmanagedbasicoperations.ManualOperationRequiredoperatorstoloadprogramsandmanageresources.ExamplesGM-NAAI/O,OS/360.Single-UserBatchProcessingSystemsOneJobataTimeProcessedjobssequentially,withoutmultitasking.LimitedResourceUtilizationCPUwasidlewhilewaitingforI/Ooperationstocomplete.ExamplesEarlyIBMsystemsusedpunchedcardsforinput.MultiprogrammingBatchSystemsMultipleProgramsEnabledmultipleprogramstoresideinmemorysimultaneously.ContextSwitchingTheCPUswitchedbetweenprogramstoimproveresourceutilization.ExampleIBM'sOS/360operatingsystem.Time-SharingOperatingSystems(cont.)UserInteractionAlloweduserstointeractwiththesysteminreal-time.ResourceAllocationSharedCPUtimeandotherresourcesamongmultipleusers.ExamplesUnix,Multics,andearlyversionsofWindows.PersonalComputerOperatingSystems1User-FriendlyInterfaceIntroducedgraphicaluserinterfaces(GUIs).2MultitaskingAlloweduserstorunmultipleapplicationssimultaneously.3ExamplesMS-DOS,AppleMacintosh,andearlyversionsofWindows.NetworkOperatingSystems(cont.)1ResourceSharingEnabledusersonanetworktosharefiles,printers,andotherresources.2NetworkManagementProvidedtoolsformanagingnetworkdevicesandusers.3ExamplesNovellNetWare,WindowsNT,andUnix-basedsystems.ParallelOperatingSystems1MultipleProcessorsDesignedtorunonsystemswithmultipleCPUs.2ParallelProcessingSplittasksintosubtaskstoexecutesimultaneouslyondifferentprocessors.3ExamplesLinux,WindowsServer,andUnix-basedsystems.DistributedOperatingSystems(cont.)DistributedResourcesManageresourcesacrossmultipleinterconnectedcomputers.DistributedApplicationsAllowapplicationstorunonmultiplemachines.NetworkTransparencyHidetheunderlyingnetworkinfrastructurefromusers.Real-TimeOperatingSystems(cont.)OperatingSystemStructureKernelThecoreoftheOS,responsibleforresourcemanagement.UserInterfaceProvidesawayforuserstointeractwiththesystem.DeviceDriversControlspecifichardwaredevicesconnectedtothesystem.FileSystemOrganizesandmanagesfilesanddirectories.Kernel1CoreComponentResponsibleformanagingsystemresources.2ProcessManagementControlstheexecutionofprogramsandallocatesresources.3MemoryManagementManagestheallocationanduseofcomputermemory.4SecurityProtectssystemresourcesfromunauthorizedaccess.UserInterfaceGraphicalUserInterface(GUI)Providesauser-friendlyvisualenvironmentwithwindows,icons,andmenus.Command-LineInterface(CLI)Usestext-basedcommandstointeractwiththesystem.DeviceDriversHardwareCommunicationEnabletheOStocommunicatewithspecifichardwaredevices.AbstractionProvideaconsistentinterfaceforinteractingwithdifferentdevices.ExamplesDriversforprinters,graphicscards,andnetworkadapters.FileSystemFileOrganizationOrganizesfilesanddirectoriesonstoragedevices.FileAccessProvidesawayforprogramstoaccessfiles.ExamplesFAT,NTFS,andExt4.ProcessManagementProcessCreationCreatesandinitializesnewprocesses.ProcessSchedulingDeterminestheorderinwhichprocessesrun.ProcessCommunicationEnablesprocessestointeractwitheachother.ProcessTerminationReleasesresourcesusedbyterminatedprocesses.MemoryManagement1MemoryAllocationAllocatesmemorytoprocessesandothersystemcomponents.2VirtualMemoryUsessecondarystoragetoextendtheavailablememoryspace.3MemoryProtectionPreventsprocessesfromaccessingeachother'smemory.SecurityManagement1AuthenticationVerifiestheidentityofusersandprograms.2AuthorizationDetermineswhatactionsusersorprogramsareallowedtoperform.3AccessContr