An object class is like a factory for producing instances. An object class creates instances and provides methods that these instances can use. At the time of its creation, an instance acquires all instance methods of the class it belongs to. If a class adds new methods later, existing instances do not acquire them. Instances created after the new methods do acquire them.
Because classes define methods for their instances, and methods define the variables instances use, object classes are a complete blueprint for creating REXX instances. The Array class is an example of an object class.