The data in a Revit document consists primarily of a collection of elements. An element usually corresponds to a single component of a building or drawing, such as a wall, door, or dimension, but it can also be something more abstract, like a wall type or a view. Every element in a document has a unique ID, represented by the ElementId class.

System Object
Autodesk.Revit.DB Element
Autodesk.Revit.DB.Analysis AnalysisDisplayLegend
Autodesk.Revit.DB.Analysis AnalysisDisplayStyle
Autodesk.Revit.DB.Analysis ConceptualSurfaceType
Autodesk.Revit.DB.Analysis EnergyAnalysisDetailModel
Autodesk.Revit.DB.Analysis EnergyAnalysisOpening
Autodesk.Revit.DB.Analysis EnergyAnalysisSpace
Autodesk.Revit.DB.Analysis EnergyAnalysisSurface
Autodesk.Revit.DB.Analysis EnergyDataSettings
Autodesk.Revit.DB.Analysis HVACLoadType
Autodesk.Revit.DB.Analysis MassEnergyAnalyticalModel
Autodesk.Revit.DB.Analysis MassLevelData
Autodesk.Revit.DB.Analysis MassSurfaceData
Autodesk.Revit.DB.Analysis MassZone
Autodesk.Revit.DB.Analysis PathOfTravel
Autodesk.Revit.DB.Analysis RouteAnalysisSettings
Autodesk.Revit.DB.Analysis SpatialFieldManager
Autodesk.Revit.DB AppearanceAssetElement
Autodesk.Revit.DB.Architecture ContinuousRail
Autodesk.Revit.DB.Architecture MultistoryStairs
Autodesk.Revit.DB.Architecture Railing
Autodesk.Revit.DB.Architecture Stairs
Autodesk.Revit.DB.Architecture StairsLanding
Autodesk.Revit.DB.Architecture StairsPath
Autodesk.Revit.DB.Architecture StairsRun
Autodesk.Revit.DB.Architecture TopographySurface
Autodesk.Revit.DB AreaScheme
Autodesk.Revit.DB AreaVolumeSettings
Autodesk.Revit.DB AssemblyInstance
Autodesk.Revit.DB BaseArray
Autodesk.Revit.DB BasePoint
Autodesk.Revit.DB BeamSystem
Autodesk.Revit.DB CombinableElement
Autodesk.Revit.DB ComponentRepeater
Autodesk.Revit.DB ComponentRepeaterSlot
Autodesk.Revit.DB ConnectorElement
Autodesk.Revit.DB Control
Autodesk.Revit.DB CurveElement
Autodesk.Revit.DB DatumPlane
Autodesk.Revit.DB DefaultDivideSettings
Autodesk.Revit.DB DesignOption
Autodesk.Revit.DB Dimension
Autodesk.Revit.DB DirectShape
Autodesk.Revit.DB DisplacementElement
Autodesk.Revit.DB DisplacementPath
Autodesk.Revit.DB DividedPath
Autodesk.Revit.DB DividedSurface
Autodesk.Revit.DB.Electrical CableTrayConduitRunBase
Autodesk.Revit.DB.Electrical CableTraySettings
Autodesk.Revit.DB.Electrical CableTraySizes
Autodesk.Revit.DB.Electrical ConduitSettings
Autodesk.Revit.DB.Electrical ConduitSizeSettings
Autodesk.Revit.DB.Electrical ElectricalDemandFactorDefinition
Autodesk.Revit.DB.Electrical ElectricalLoadClassification
Autodesk.Revit.DB.Electrical ElectricalSetting
Autodesk.Revit.DB.Electrical PanelScheduleSheetInstance
Autodesk.Revit.DB.Electrical PanelScheduleTemplate
Autodesk.Revit.DB ElementType
Autodesk.Revit.DB ElevationMarker
Autodesk.Revit.DB ExportDGNSettings
Autodesk.Revit.DB ExportDWGSettings
Autodesk.Revit.DB.ExtensibleStorage DataStorage
Autodesk.Revit.DB FabricationConfiguration
Autodesk.Revit.DB FabricationPart
Autodesk.Revit.DB FaceSplitter
Autodesk.Revit.DB Family
Autodesk.Revit.DB FilledRegion
Autodesk.Revit.DB FillPatternElement
Autodesk.Revit.DB FilterElement
Autodesk.Revit.DB GraphicsStyle
Autodesk.Revit.DB Group
Autodesk.Revit.DB HostObject
Autodesk.Revit.DB ImageInstance
Autodesk.Revit.DB IndependentTag
Autodesk.Revit.DB Instance
Autodesk.Revit.DB KeyBasedTreeEntryTable
Autodesk.Revit.DB LinePatternElement
Autodesk.Revit.DB Material
Autodesk.Revit.DB.Mechanical DuctSettings
Autodesk.Revit.DB.Mechanical DuctSizeSettings
Autodesk.Revit.DB.Mechanical MechanicalEquipmentSet
Autodesk.Revit.DB.Mechanical Zone
Autodesk.Revit.DB MEPSystem
Autodesk.Revit.DB ModelText
Autodesk.Revit.DB MultiReferenceAnnotation
Autodesk.Revit.DB MultiSegmentGrid
Autodesk.Revit.DB NestedFamilyTypeReference
Autodesk.Revit.DB NumberingSchema
Autodesk.Revit.DB NumberSystem
Autodesk.Revit.DB Opening
Autodesk.Revit.DB ParameterElement
Autodesk.Revit.DB Part
Autodesk.Revit.DB PartMaker
Autodesk.Revit.DB Phase
Autodesk.Revit.DB PhaseFilter
Autodesk.Revit.DB.Plumbing PipeSettings
Autodesk.Revit.DB PrintSetting
Autodesk.Revit.DB ProjectInfo
Autodesk.Revit.DB PropertyLine
Autodesk.Revit.DB PropertySetElement
Autodesk.Revit.DB ReferencePoint
Autodesk.Revit.DB Revision
Autodesk.Revit.DB RevisionCloud
Autodesk.Revit.DB RevisionSettings
Autodesk.Revit.DB ScheduleSheetInstance
Autodesk.Revit.DB Segment
Autodesk.Revit.DB SketchBase
Autodesk.Revit.DB SketchPlane
Autodesk.Revit.DB SpatialElement
Autodesk.Revit.DB SpatialElementCalculationLocation
Autodesk.Revit.DB SpatialElementTag
Autodesk.Revit.DB StartingViewSettings
Autodesk.Revit.DB.Structure AnalyticalLink
Autodesk.Revit.DB.Structure AnalyticalModel
Autodesk.Revit.DB.Structure AreaReinforcement
Autodesk.Revit.DB.Structure BoundaryConditions
Autodesk.Revit.DB.Structure FabricArea
Autodesk.Revit.DB.Structure FabricSheet
Autodesk.Revit.DB.Structure Hub
Autodesk.Revit.DB.Structure LoadBase
Autodesk.Revit.DB.Structure LoadCase
Autodesk.Revit.DB.Structure LoadCombination
Autodesk.Revit.DB.Structure LoadNature
Autodesk.Revit.DB.Structure LoadUsage
Autodesk.Revit.DB.Structure PathReinforcement
Autodesk.Revit.DB.Structure Rebar
Autodesk.Revit.DB.Structure RebarContainer
Autodesk.Revit.DB.Structure RebarCoupler
Autodesk.Revit.DB.Structure RebarInSystem
Autodesk.Revit.DB.Structure ReinforcementSettings
Autodesk.Revit.DB.Structure StructuralConnectionHandler
Autodesk.Revit.DB.Structure StructuralConnectionSettings
Autodesk.Revit.DB.Structure StructuralSettings
Autodesk.Revit.DB.Structure Truss
Autodesk.Revit.DB SunAndShadowSettings
Autodesk.Revit.DB TextElement
Autodesk.Revit.DB View
Autodesk.Revit.DB ViewNavigationToolSettings
Autodesk.Revit.DB Viewport
Autodesk.Revit.DB ViewSheetSet
Autodesk.Revit.DB WorksetDefaultVisibilitySettings
Autodesk.Revit.DB WorksharingDisplaySettings