Behavioral patterns are concerned with the assignment of responsibilities between objects, or, encapsulating behavior in an object and delegating requests to it. Chain of responsibility, Command, Mediator, and Observer, address how you can decouple senders and receivers, but with different trade-offs.
Creational patterns In software engineering, creational design patterns are design patterns that deal with object creation mechanisms, trying to create objects in a manner suitable to the situation. The basic form of object creation could result in design problems or added complexity to the design.
A structural design pattern serves as a blueprint for how different classes and objects are combined to form larger structures. Unlike creational patterns, which are mostly different ways to fulfill the same fundamental purpose, each structural pattern has a different purpose.