Design Patterns are typical solutions to commonly occurring problems in software design. They are like pre-made blueprints that you can customize to solve a recurring design problem in your code.

3 main groups of patterns:

• Creational patterns provide object creation mechanisms that increase flexibility and reuse of existing code
• Structural patterns explain how to assemble objects and classes into larger structures, while keeping these structures flexible and efficient
• Behavioral patterns take care of effective communication and the assignment of responsibilities between objects

• Factory Method
• Abstract Factory
• Builder
• Prototype
• Singleton

• Adapter
• Bridge
• Composite
• Decorator
• Facade
• Flyweight
• Proxy

• Chain of Responsibility
• Command
• Iterator
• Mediator
• Memento
• Observer
• State
• Strategy
• Template Method
• Visitor