DisplayList, DisplayObject, and DisplayObjectContainer
DisplayList consists of three major elements: 'Stage', 'DisplayObjectContainer', and 'DisplayObject'.
'Stage' is an object that holds all 'DisplayObject'.
'DisplayObjectContainer' is a 'DisplayObject' that can be used to place DisplayObjects, and it inherits from the following four classes.
'DisplayObject' is an object that executes the drawing process. 9 classes inheriting from 'DisplayObject' are as follows.
To add a 'DisplayObject' to a 'DisplayObjectContainer', use the addChild method of the DisplayObjectContainer.