BenefitsIt lets you add or remove objects at runtime.It lets you specify new objects by varying its values or structure.It reduces the need for subclassing.It lets you dynamically configure an application with classes.
Applicable ScenariosThe classes to instantiate are specified at runtime.You need to avoid building a class hierarchy of factories that parallels the hierarchy of objects.Instances of the class have one of only a few different combinations of state.
