System objects
PowerBuilder system class objects are the built-in objects you use to develop your application. PowerBuilder system objects include objects such as windows and menus, as well as graphical controls and predefined entities that you can reference in your application, such as the Message and Error objects.
Controls
PowerBuilder controls are a subset of system objects that you place in windows or user objects. Typically, they are graphical objects that allow users to interact with your application or that you use to enhance the design of your windows.
System structures
PowerBuilder system structures are a subset of system objects that contain properties that describe the state of other system objects or the system itself. For example, the Environment object is a structure that holds information about the computing platform the PowerBuilder Application object is running on.
