Graphical objects, also known as entities, are the visible objects (lines, circles, raster images, and so forth) that make up a drawing. To create these objects, use the appropriate Add<Entityname> method. To modify or query these objects, use the methods or properties of the object itself. Each graphical object has methods that allow an application to perform most of the AutoCAD editing commands such as Copy, Erase, Move, Mirror, and so forth. These objects also have methods for setting and retrieving extended data (xdata), highlighting and updating, and retrieving the bounding box of the object. Graphical objects have typical properties such as Layer, Linetype, Color, and Handle. They also have specific properties, depending on their object type, such as Center, Radius, and Area.
Nongraphical objects are the invisible (informational) objects that are part of a drawing, such as Layers, Linetypes, DimStyles, SelectionSets, and so forth. To create these objects, use the Add method of the parent Collection object. To modify or query these objects, use the methods or properties of the object itself. Each nongraphical object has methods and properties specific to its purpose; all have methods for setting and retrieving extended data (xdata), and deleting themselves.