Chain of Responsibility is a behavioral design pattern that lets you pass requests along a chain of handlers. Upon receiving a request, each handler decides either to process the request or to pass it to the next handler in the chain.

Behavioral design patterns are concerned with algorithms and the assignment of responsibilities between objects.

Singleton is a creational design pattern that lets you ensure that a class has only one instance, while providing a global access point to this instance.

Prototype is a creational design pattern that lets you copy existing objects without making your code dependent on their classes.

Builder is a creational design pattern that lets you construct complex objects step by step. The pattern allows you to produce different types and representations of an object using the same construction code.