Main categories of design patterns

There are three basic classifications of patterns Creational, Structural, and Behavioral patterns.

Creational Patterns

• Abstract Factory:- Creates an instance of several families of classes
• Builder: - Separates object construction from its representation
• Factory Method:- Creates an instance of several derived classes
• Prototype:- A fully initialized instance to be copied or cloned
• Singleton:- A class in which only a single instance can exist

Note: - The best way to remember Creational pattern is by remembering ABFPS (Abraham Became First President of States).
Structural Patterns

• Adapter:-Match interfaces of different classes .
• Bridge:-Separates an object’s abstraction from its implementation.
• Composite:-A tree structure of simple and composite objects.
• Decorator:-Add responsibilities to objects dynamically.
• Façade:-A single class that represents an entire subsystem.
• Flyweight:-A fine-grained instance used for efficient sharing.
• Proxy:-An object representing another object.

Note : To remember structural pattern best is (ABCDFFP)
Behavioral Patterns

• Mediator:-Defines simplified communication between classes.
• Memento:-Capture and restore an object's internal state.
• Interpreter:- A way to include language elements in a program.
• Iterator:-Sequentially access the elements of a collection.
• Chain of Resp: - A way of passing a request between a chain of objects.
• Command:-Encapsulate a command request as an object.
• State:-Alter an object's behavior when its state changes.
• Strategy:-Encapsulates an algorithm inside a class.
• Observer: - A way of notifying change to a number of classes.
• Template Method:-Defer the exact steps of an algorithm to a subclass.
• Visitor:-Defines a new operation to a class without change.