Intent Creational Class Factory Method Define an interface for creating an object, but let subclasses decide which class to instantiate.
Factory method lets a class defer instantiation to subclasses.
Convert the interface of a class into another interface clients expect. Adapter lets classes work together that couldn t otherwise because of incompatible interfaces. Convert the interface of an object into another interface clients expect. Adapter lets classes work together that couldn t otherwise because of incompatible interfaces. Structural Object Bridge Decouple an abstraction from its implementation so that the two can vary independently Structural Object Composite Compose objects into tree structures to represent part-whole hierarchies.