The Map class is primarily used to contain and organize map content or MapItems. A MapItem represents an entity that can be stored in a map, for example the ArcGIS Explorer types: Note, View, Folder, Link, ImageOverlay and Layers. You can add an item to the Map using the Map.ChildItems property, a collection that can store any derived MapItem type .

A Map cannot be explicitly instantiated; it is always obtained using the MapDisplay.Map property. The ChildItems property enables you to manage the content stored by a map; it is a MapItemCollection that you can add to and remove from. Add a MapItem to the collection and it will be added to the Map in the application. The ArcGIS Explorer application will respond in different ways depending on the type of MapItem you add. All ChildItems will be displayed in the application content window, however only MapItems with associated graphics (Notes) or spatial data (Layers) will be drawn on the Map.

The order of the Map.ChildItems collection dictates the order in which items are presented in the ArcGIS Explorer contents window. By default, items are added to the end of the collection and will display at the bottom of the content hierarchy. If you wish to add items to the top of the hierarchy use the MapItemCollection.AddFirst method.The order of the Map.ChildItems collection does not influence drawing order of layers or image overlays contained by the Map.

The layer classes are a subset of MapItems that reference geographic data. When a layer is added to the Map, the related data is draped over the basemap or, if applicable, used as a terrain elevation source in 3D. Geographic data can be stored in a variety of formats typically in a file or geodatabase. The drawing order of Layers in a map is controlled using a LayerOrderCollection object obtained from the Map.LayerDrawingOrder property. You cannot add or remove layers directly from the LayerOrderCollection: the contents of the collection are driven by the layers currently contained by the Map. Each layer has a DrawIndex property that returns the indexed position within the LayerDrawingOrder collection. When a layer is added to the Map, it is automatically added at a DrawIndex of zero, which means it draws on top of other layers in the Map. The LayerOrderCollection class has methods to change the order in which layers are drawn on the Map: Move, MoveUp, MoveDown, MoveToTop and MoveToBottom.

A similar pattern is used to control the drawing order of ImageOverlay objects contained by the Map; an image overlay is an image that is drawn in relation to the Map window rather than draped onto the Map. The drawing order of Layers in a map is controlled using a LayerOrderCollection object obtained from the Map.ImageOverlayDrawingOrder property.