In contrast to common illustrations, "intelligent" illustrations reference one or more graphical objects.  These references can be recognized through identification numbers (IDs), as well as by the hotspot information of each respective object.

Common illustrations
Common illustrations simply mediate and display visual information. Exploded view drawings in a spare parts catalog, which essentially present all parts in a recognizable form of display, are an example of common illustrations.

Common illustrations typically contain non-structured graphic information that does not allow reference to real objects. In such illustrations, it is hardly possible for a program to identify the lines belonging to a logic entity, such as a spare part. 

Intelligent illustrations
In intelligent illustrations, the "unsorted" graphic information of an illustration is structured as groups of single elements. Each group contains information referencing an object. Moreover, every group is assigned a name for identification. The resulting "graphical object" can be identified by this name.

At this point, all catalog functions can access these graphical objects, which serve as variables for corresponding real objects. A hotspot contour can be added to graphic objects also, which can later be used as a link source for mouse clicks in the electronic catalog. In intelligent illustrations, not only can all graphic (single element) information be saved in an illustration file, but the corresponding hotspots can be included as well.