Design Patterns were initially grouped into the categories creational, structural and behavioural.

Lazy Loader is an initialisation pattern that (for example) instantiates an empty object but does not populate the object until it is required.

Proxy is a structural pattern that provides a surrogate of an object to control access to it.

Adapter is another structural pattern that converts the interface of an object into the interface that another client expects. Adapters let objects work together that otherwise not work due to incompatible interfaces.

Pipes and Filters Implement the transformations by using a sequence of filter components, where each filter component receives an input message, applies a simple transformation, and sends the transformed message to the next component. Conduct the messages through pipes [McIlroy64] that connect filter outputs and inputs and that buffer the communication between the filters. [Microsoft]