layer

(Map) The IlvMapLayer class represents a map layer, that is, a cartographic theme. It associates a style, IlvMapStyle or one of its subclasses, with an IlvManagerLayer that contains graphic objects.

(JViews Framework) Storage area of manager in which graphic objects are placed. A manager uses multiple layers, referenced by index numbers. Objects in a higher-numbered layer are displayed in front of objects of a lower-numbered layer.

load-on-demand

Load-on-demand is a mechanism that lets you load into memory only the portion of a map that you want to view. This capability is implemented via a specific manager layer, called a tiled layer.