Abstract Factory - creates an instance of several families of classes
Builder - separates object construction from its representation
Factory - creates an instance of several derived classes
Prototype - a fully initialized instance to be copied or cloned
Singleton - a class of which only a single instance can exist

Structural: deals with class & object composition
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Adapter - match interfaces of different classes
Bridge - separates an object's interface from its implementation
Composite - a tree structure of simple and composite objects
Decorator - add responsibilities to objects dynamically
Facade - a single class that represents an entire subsystem
Flyweight - a fine-grained instance used for efficient sharing
Proxy - an object representing another object

Behavioural: deals with the communication between classes & objects
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Chain of Responsibilities - a way of passing a request between a chain of objects
Command - encapsulate a command request as an object
Interpreter - a way to include language elements in a program
Iterator - sequentially access the elements of a collection
Mediator - defines simplified communication between classes
Memento - capture and restore an object's internal states
Observer - a way of notifying change to a number of classes
State - alter an object's behavior when it's state changes
Strategy - encapsulate an algorithm inside a class
Template - defer the exact steps of an algorithm to a class
Visitor - defines a new operation to a class without change